What can you do when you are driving?? (Sexual knowledge adult novel)

This is my first post, so please forgive me for my poor writing skills. My wife and I have been married for about 2 or 3 years. We occasionally go out on our anniversaries, including birthdays and wedding anniversaries. Especially when it is my birthday, I can do whatever I want. As long as it is not too excessive, my wife will turn a blind eye.
Last year, I took my wife to a hot spring bath on my birthday. My birthday was in November. It took at least an hour and a half to drive from my home to Jinshan. However, the hot spring bath was just a cover. Having sex in the hot spring suite was my main goal. However, the journey was too far. While I was driving, I put my hand under my wife's skirt.
I started teasing her. Actually, it was not the first time. She didn't feel anything at the beginning, but gradually she started to feel it. Plus, the road conditions were not very good and it was bumpy. When I touched her, it felt like a vibrator. She moaned so loudly that it scared me. I think very few people have this experience. Sometimes when I go on long trips with my wife, especially on highways, because I am the only one driving, on the way back sometimes I almost close my eyes. My wife (then my girlfriend) would ask me if I wanted to rest, and I would say no. However, I would ask her to touch my penis, and I would tell her that this would make me feel better. In fact, she knew I was talking nonsense, but she still cooperated with me. In fact, there are many things to do in the car, but now I am more restrained. Let me share this experience with you.