How do I make my brother clean our car?

Me and my twin brother share a car together. He has a girlfriend and sometimes they go out to buy ice-cream or something together. Anyways, they never seem to clean up their mess and it’s breaking my balls.

Last time I cleaned the car I found some rotten ice-cream leftovers under one seat. There were melted caramels in the cup-holders (which I don’t dare to touch) and the car smelled like shit.

I decided to wait for him to clean it but every time it annoys me to the point that I clean it myself. It also annoys me that every time I mention it to him that he should clean the car he goes ape-shit on me and starts shouting about that the car is clean enough to drive it. He then starts to argue that he doesn’t have time to clean it but every night he just plays video games for 3–4 hours and often then I mention it to him to clean the car but he doesn’t bother.

This is driving me crazy, what should I do about it?