I had a similar experience, I had gone to a dealer who proceeded to shop me around to six different underwriters. Ridiculous, I was caught completely unawares.
As far as impact, I still get chicken skin every time I see all of those inquiries (six months before they completely fall off), but at the end of the day I did get approved.
May I recommend saving the inquiries? Pull your own report, take it to some credit unions and see if they'll work with your history. If they're willing to put together a good rate, give them the go-ahead to pull a hard inquiry (I think they all require their own in this day and age), and as long as the info matches your report, you should get the same rates promised. I did that last week and went from a 14.5% (so much for that dealer shopping the 'best' rate, huh?) to 7.5%, and with only one hard inquiry.
Good luck...