Well, for a college kid who'd had a total of 2 blowjobs in his entire life, nothing sounded better at that moment. I said something like "hell yes!" He stopped jacking me and just cupped his fingers around my balls. An exit was coming up and he slid the car over to take it. I just leaned back in the seat and enjoyed the feel of his hand on my balls.
Just off the exit ramp was a large truck stop. The parking lot was huge and there were not many cars or trucks there at that time. He pulled to a remote corner, looked me in the eye and said "I think you'll enjoy this". Thank God for a late '70's Cadillac, the front seat was huge and he had plenty of room to stretch out and have his face meet my cock.
I felt his lips wrap around me and got a surge of energy from that. He started to slowly move up and down my shaft, but as a 19 year old undersexed, overstimulated horn dog, I found my ass starting to move and began to thrust my cock into his mouth. He placed one hand on my ass and massaged it as he continued to bob on my cock and I continued to piston it in and out of his mouth.
It didn't take long for me to build to a climax. Just as I was about to explode I put my hand on the back of his head and pulled him down onto my cock. He didn't deep throat me but definitely got more of his mouth around me and I was in heaven when I exploded. It was definitely the most intense orgasm I had ever had... the spasms lasted for close to minute, with me pulsing into his mouth over and over. To his credit, he swallowed almost all of it, only letting a little dribble out the corner of his mouth.
At that point I was spent, both physically and mentally, as this was such a new and unique experience for me. I just sat back and closed my eyes and enjoyed the afterglow. I heard the car start up and move off and we were back on the highway. At this point we were probably 20 minutes away from my destination. We drove in silence at first, then he began to talk a little, telling me how much he enjoyed my cock, how sweet my cum was, etc, etc. That led to him asking me for my phone number. I lived with two (straight) roommates at college and did not want him talking with them. I said I couldn't give it to him, which seemed to disappoint him, but que sera. I directed him to drop me about 2 blocks from my house as I didn't want him to know where I lived. As much as I enjoyed the experience, he was definitely not my type and I wasn't really interested in seeing him again.
I have very fond memories of the whole experience, it helped me get comfortable with my sexuality. It also gave me my first shot of confidence that I could assert a level of control in sexual situations, which was an interesting eye opener for me.