Highway

 Make my heart race.  That was on her list  when she gave in her contract. There was the usual spank me for this, reward me with plugs and leashes, choke me this much, etc. That was months ago but they've never really touched on this topic.  He's never brought it up for clarification and she's never asked, but their play time has never seemed to lack anything.  He spanks hard with his broad hands and he's managed to make her almost pass out a few times being choked while she orgasmed on his table. They don't live together so it makes his arrival more exciting, whether he's coming over after work at night or he surprises her on his days off and tells her to call out and prepare the ropes and gags. Their journey has been interesting and she was happy to be his Sub.

It was a hot summer this year and August hit a hundred twice and tonight was set to be dry in the 90's. Sir was never too detailed in his requests, so when she got his text she knew to act swiftly. "Put on your satin slip and coat, no underwear. Wait at the door in 30 minutes."  A text that put a smile on her face regardless of what it said, as long as it meant being in Sir's presence and earning a reward or a punishment; it just meant being safe.  So she hopped to it and got ready. Prompt as always, Sir knocks the door on time and she opens.
"Goodnight Sir".
"Hi baby, turn around."
Her heels clicked the hardwood floor of her apartment as her 3 steps confirmed her turn. Sir reached up and blindfolded her. Then, something unusual was done next.  Sir had rope that she did not see and he did a basic chest harness with an arm tie over her clothes.  Curiosity set in as she would normally be naked on the rack or the table being tied. But she was at the stage where trust was high. The next unusual thing was that he walked her outside in the pitch black darkness instead of into her living room or bedroom. The hot night air brushed her cheek letting her know that it's not cold but had no secrets to share of what would happen next.  Her heels clicked towards his car, the door opens and he helps her in and clicks in her her seatbelt. Blindfolded, tied up and now seatbelted in. When Sir came in on the driver's side, all the sounds of someone getting in and setting up to drive was now more profound in her ear.  The clicks and creaking leather, the slight rocking of the car, the quick fumble of car keys and the final engine startup.
She didn't worry as they drove, his car was tinted, it's after 1am, who would notice and bound and blindfolded passenger being driven around. His car had a voice alert for high speeds.  An automated female voice would call the speed every ten miles per hour over the speed limit. 
"60-miles-per-hour",she said.
It was a feature he just didn't turn off yet as he just got the car a few days ago and was still getting used to it.  So she ignored it but it was cute to her that he couldn't observe the speed limit as she kept hearing the 60 miles per hour notice. Soon she felt an unusual deceleration, tires on gravel instead of asphalt and then stopped. Did they get pulled over? Maybe a cop saw him speeding and now he's going to have to explain why his passenger and blindfolded and tied up.  But there were no sirens and no "oh shit" being gasped from her host, so what was wrong? What she did not know was tonight was the night Sir had planned to honor that missing item on her list.  She could not see that he had just joined the highway and pulled over on the shoulder.  She did not see the knife Sir had on the backseat and was totally unaware of what was next. 
She hears the mechanism for the convertible top engage and as it opened the hot night air wafted over her. He got out and now his footsteps tapped the gravel as he made his way around the car. Her door opens and all she feels next, quickly, viciously, is Sir ripping open her coat and 2 buttons hitting the dashboard, then his deliberate hands pulling and slicing open her satin slip revealing her naked body, with her breasts perked up in the rope harness.  Some of the coat was caught in it but he manhandled enough of it to leave her exposed.  The brash speed of it left her breathing quickly and a little nervous even though her mouth half open in a wonderlust of what's next. She hears a familiar sound, his belt buckle loosening. But why drive her out here just to shove his dick in her mouth on the side of the road? And she was right, that was not what Sir had in mind. He put the belt around her neck and looped it on the headrest, not to choker as she would have enjoyed but to hold her firm and affixed to the bucket seat of this sports car.
Door slams, footsteps, Door slams, engine revs and he launches the car, peeling gravel and she hears the pebbles hitting the ground after being shot in the air. Sir floored the car and sped off once the tires found asphalt.  Within seconds, "sixt-miles-per-hour". she was now scared and excited. Seventy-miles-per-hour and the car dodges left and right!  He was overtaking other cars as the engine still raced faster.  The hot night air now whipping over her body, exposed nipples and whisking between her legs. The dodging continues and you hear the engine howling.  Eighty-miles-per-hour it said, her body being lashed by the hot night air was now starting to scaring her. The care lobbed all the way to the right then all the way to the left and you could hear little screeches of the wheels as she felt he might be losing control of the car.  While the fast hot air made her nipples hard, the resistance of the belt felt like a choke and the whisking air between her legs made her hips start to grind on the leather seat.
"Ninety-Miles-an-hour" and she started to hear his breathing, steady, concentrated. But her breathing was now hyper, and her knees buckled together out of fright.  No arms to hold on to anything and her belted neck stopping her from dipping her head down.  Worse, being blindfolded heightened what she could not see. "One-Hundred-Miles-Per-Hour" and he reaches over, grabs her knee and yanks it apart. "keep your legs open you little slut".  The fright makes her hips gyrate but that same motion rubs her wet clit on the leather seat, scared but it feels good now, frightened but it was like being dangled over a cliff, you're secure but you're seeing the fall in your entire body.
"One-Hundred-Ten-Miles-Per-Hour" and Sir reached over and pinched her nipples and started to rub her breasts with those broad hands. He moved his hands up, passing over her neck, up passed her ear and then grabbed a rough handful pulling back.  All these sensations raced down between her legs like lightening bolts. But he's driving with one hand! "One-Hundred-Twenty-Miles-Per-Hour" and he grabs her jaw squeezing her lips and says.
"This is what you wanted huh you little slut, isn't it"
Barely able to breathe between being scared, horny, her wet thighs, clit rubbing on the leather and now her mouth squeezed, "yes Sir" slightly muffled.
"Didn't you?!"
"Yes Ss.." and she convulsed right into an orgasm.  He body heaved and pulled and shuddered as he held tight on her face. He could feel her heavy breathing on his finger and he smiled.  He slows the car by just letting off the gas and pulls over. He gets out and rescues her from the bucket seat and made her stand up.  Removing the blindfold then kissing her, eyes remained closed as she held him closely, her quivering, naked and now cold body weaved into his coat that he had on.  Sir was prepared for aftercare as he had new clothes and a new coat for her in his trunk that he bought earlier that day.  Once she opened her eyes and looked up at her man, she said "Thank you Sir".  He smiled and said "Good girl".  Helped her with her clothes, put the ripped coat on the seat while saying with a chuckle, "this chair is officially yours now babe". Blushing was her only possible response.  He revved up, found the next U-turn and drove her home where they made love one more time and slept curled up till sunrise.