Is There A Way I Can Get My Money Back For A Car I Paid Half Of?

So my best friend (let’s call him M) and I moved out to Seattle, WA together when I had gotten my new job. We were living with my aunt who invited us up to stay with her until we got back on our feet. My best friend got a job at subway and we saved up some money to move out. In the meantime, my aunt had bought us a car of our own and we were paying her back $200 a month until it was fully paid off. M and I decided that it was best to say we split the car evenly when it came to finances. So that’s what we did. He paid for half and I paid for half. However, everything was under M’s name. Title, insurance, everything. We also didn’t have a written agreement saying who would receive the car if one were to move out. Well, the car was paid off (it was total of $1,100) and even though I made a lot more money at my job than he did at his, I still agreed to split the cost of the car down the middle where we each just paid half of everything. Keep in mind I don’t drive because I don’t have a license and I’m working towards one right now. So I brought in the money for the apartment and utilities while M drove me to and from work every morning. (We paid it all back to my aunt) several months later, we had gotten into many arguments (not over the car, over other things) and I ended up throwing M out. He went and stayed with his boyfriend and my boyfriend moved in. A month later, I was laid off from my job forcing my boyfriend and I to move in at his mother’s house (which we still live in) Now that I don’t have an income (I’ve been having problems at the unemployment office, trying to reach someone, etc.) I could use the half I paid for and M promised me that even though we weren’t friends anymore that he would still give me half of what I paid for once he sold the subaru. I agreed to that. A week later, M had informed me that he traded in the subaru for a cadillac (moron) and only got $300 from the trade-in. He still owes $6,000 on the cadillac and since I know for a fact that he doesn’t have a leg to stand on or a penny jar to call his own, I’m offering to make him a deal. The deal is: Instead of giving me half of what I paid for the car, I want him to buy me a big bag of tobacco and 2 boxes of tubes every four months (the cost of a big bag of tobacco and tubes are approximately $45-$50) and each time he gets me tobacco and tubes, I’ll mark it off of his debt. (I’m not working right now and I can’t anyway, doctor’s orders for a few months) otherwise I’d be looking for a job right now. AND the best perk of the deal is that I won’t even charge him half of what I paid for, I’ll just charge him for whatever he got off of the trade-in.
If he doesn’t go for this deal (which is a pretty darn good deal in my opinion) Is there ANYTHING I can do to get my half of the car back? I can prove I paid for it, heck I can prove I paid for the whole thing because every single payment made came out of MY bank account to my aunt who I KNOW would back me up on this. Any suggestions or tips? What can I do at this point? No written agreement and everything was under his name. Thanks =)