Big and loud cars are antisocial and should be forbidden to drive as a private person. CHANGE MY MIND
Cars are a very big carrot for hard work. They are the modern status symbol and toy which is available for entry to all budgets. Generally, big cars are luxorious, loud cars are fast. No one is gonna work their ass off to move from a 2003 Prius to a 2025 Prius. Plenty of people work their ass off to get a sexy car and to keep it on the road.
Edit: Missed the status symbol itself being stressful. I don't think so. There's a lot of pride in just your status moving up. You get a 90s 7 series, you're happy as hell because it's yours. Moved from daddy's money to self sufficient. Your first car. Then you get a nice 00s 5 series, we moving up in the world. Then you get an old Jag as a weekend thing, oh shit, we getting fancy. It just gives you a pleasant feedback loop every year to couple years.
"Loud" can be defined as dB, perhaps a distance from the source of the sound or from a neighborhood/business etc. Ex. Any sound you produce much have adequate dampening or distance such that school zones and residential zones do not recieve greater than 75dB from any singular source, nor 90dB from the combination of all sources. Then legally concerts must use different venues, planes must take a more difficult path to avoid the nearby airport neighborhoods, etc. Maybe walls erected next to speedways.
"Big" would probably need greater specification. One that already exists is lane width, so you can base things off that. Ex. Single-axle vehicles may not have a height greater than its width, where width is measured as the distance between lugnuts in the tightened position of the left and right wheels, the greater distance if the front and back wheels are at different distances.
2. IT'S AMERICA!!!
/s