
You have some ability to customize the interior of your car to help you deal with situations you encounter as you drive.
If you want to relax, the traffic has gotten your blood pressure up to really impressive levels, spritz the inside of your car with the scent of lavender, lemons, or oranges. Want help keeping your mind from wandering? Smelling rosemary or peppermint may help some.
Hearing traffic and sounds made by your car and around it are important for your safety. If you decide to add sounds to your drive beyond the road sounds, etc., and want to relax, try quietly playing a nature soundscape, the sorts of acoustic environment you’d encounter in a meadow on a lovely spring day. Need to perk yourself up. Do the obvious—play something with a rapid beat (some music you enjoy would be best here) at a loud but safe volume.
Keep your car neat to keep yourself happy, well, at least as happy as you can be speeding along the freeway with some idiot driving right on your tail. Receipts lying around, crisp packets, etc., boost the visual complexity inside your car, which is a no-no as detailed here LINK and also send a not-so-positive message to you (and whoever can see into your car) about your values and life priorities. The same goes for scratches in your car’s paint, surface dirt that gets so thick that passers-by write messages to you in it, etc. If you have a blow-up monkey in the back seat of your car, you know why it’s there, but don’t be surprised if your neighbours treat you differently after they get a look at your travel companion.