I'm definitely not an expert, these are just my thoughts.
Attempted false pretenses with respect to money the mechanic was going to charge Alice for the bogus repairs (if that was his plan). He misrepresented to Alice that the car needed repairs.
Larceny with respect to the hubcaps. There is arguably caption and asportation since he took control of the car and drove it. Failing that, attempted larceny for the hubcaps.
Prosecution might try larceny for the car. I think this would fail though because I don't see how the mechanic could have had a superior possessory interest over the car. The only even vaguely reasonable thing is a mechanic's lien and I don't see any good argument supporting one.
If prosecution could somehow get larceny to stick, then possibly burglary depending on how the burglary statute is written. Otherwise, probably some sort of breaking and entering, with a possible defense raised by the mechanic being a crook, Alice having credible information to that effect, etc.
Also maybe felony murder, depending on how the felony murder statute is written, and assuming the prosecution could stick Alice with a qualifying predicate felony (burglary would probably be a good one).