Kev, go to Hassel.
I've been going there with my current car and my previous bmw as well, I think they do a great job. Call Paul Giaquinto or Kati Arcadi at 516-868-4554.
The one thing I'm not sure about, is if they will give you a loaner if you didn't buy the car from them. However even if they don't, they have the LIRR 2 mins away and will drive you over/pick you up.