I think theres a best western on 48th just off broadway which has parking and pretty good location, not far from times square, empire state building and shopping
Honestly you are probably better off subletting a place for a week or go to one of those sort of unadvertised hotels where it is in Manhattan but not at the ridiculous prices that tourists pay.
I booked via hotwire, was rather easy to know which hotel I'd end up in thanks to the description of the hotel's amenities. Rate for the HI was 145$/nt and I liked the location. Rooms are nothing special, but clean and from what I've heard rather spacious for Manhattan.