Personally I'd ditch the car and buy a used one with way less problems than the one I currently have. Normally, bad piston rings often stem into more engine problems and you may have to replace the whole engine as a whole or get the top part overhauled (which also costs good money, somewhat on par with a used car) and if you're on a budget, that's definitely a no-go. I'd rather sell my bitcoins to fiat and just hope for the best, at least I used the coins into a useful cause compared to just having it sit there and hope that something will happen. Also, it will be one of your first purchases/expense with bitcoin (in a non-direct fashion) so it's a good thing. Emergency money should never be used in situations such as this, that's why you call it 'emergency' for a reason.
Also, this is more of a personal financial advice rather than a bitcoin-related matter. Take what I said with a grain of salt, and the final decision would always be yours as it is your money.`
If I would be in his position, I would probably do the same thing as mentioned above.
Buy a second-hand car with good history rather than trying to fix his old car that might cost him more later on/buying a new one.
Buying a new one might not be practical at his present situation.
And as someone also brought up, I think there's no problem selling his bitcoin if he bought it at a much lower price than 9.5k, right?
He already gained profit and he is addressing his daily issue in terms of transport. So I guess, he's already in the win-win situation.