In case this is helpful for anyone: If you're willing to do some of the work yourself a place like Bike Sauce or Bike Pirates would work (non profit and run by volunteers). They won't just straight up do it for you, but they'll walk you through it/assist.
Edit: it's been helpfully pointed out you meant car mechanic. But I'll leave this up partially because it's funny, and partially in case it's ever of use to anyone anyway.