"I miss being able to blast music while my sims drive in The Sims 2. I wonder why EA ever took that feature away in The Sims 3. This mod isn't perfect, but it was the easiest solution and it works. The script I used is from EA's store content vehicle the Classically Cool Fixer-Upper. Enjoy!
All vehicles except motorcycles, bicycles, scooters, boats, police cars, hovers, taxis, relocation rover, service, limos, store content, and custom content work with this mod. If you want other vehicles to have the same functions then use S3PE to copy the script from the Classically Cool Fixer-Upper and replace. If your sims are driving a 4 seat vehicle only 2 sims in the front will be visible.
I want to explore the possibility of making the back seats usable, but for now I don't know. Sims will autonomously use different functions of the car that came with the Classically Cool Fixer-Upper script. It will look weird, but there are ways to disable autonomy with Nraas. If this doesn't bother you then you can leave it as is because it doesn't cause any game breaking issues/glitches.