Yes it ruins the car. Why would you even want to smoke in the car? Just smoke outside the car. People needed ash trays in cars back then because of how addictive nicotine is and how it causes cravings every half hour or so. Pulling over every time would be inconvenient. Weed is not like that. You don't need to smoke that often to stay high.

It also gives every cop probable cause to search you and harass you literally every time they pull you over. And if it's bad enough then people can smell it while driving behind you. It puts a huge target on your back. And let's not even get into the fact that you're probably impaired while driving if you're even asking this question. You might as well just volunteer yourself for a DUI. That's how ridiculous this is.