It looks like it would be a lemon if they have had 3 attempts to fix it or it has been out of service for 30 calendar days.

We have no lemon law here, our consumer protection is far more ambiguous but I gave the garage a written rejection of my car and requested a written reply within 14 days. During this period we did have a number of discussions and in the end I asked the dealer principal to fight my case with BMW UK and insist on a replacement car, he did this for me and we have a brand new car on order and the garage have kept my old one.

I did take legal advice from my solicitor but I had legal cover with my household insurance policy so it didn't cost me anything, not sure if you folks in the US have anything similar?

Good luck and don't back down!