1. Report them to the FTC. Requiring the paint sealant package as a condition of being approved for a loan is ILLEGAL in the US. Same for the GAP insurance.
2. Report them to your State Attorney General
3. SUE THEM IN DISTRICT COURT. You should have no trouble finding a competent attorney who will take your case on a contingent fee basis.
Although I have no doubt that some F&I manager tried getting you on the back end, there are several things you don't understand.
First of all, the interest rate has nothing to do with the price of the vehicle.
That was a lie too. These scum sell you at a higher rate, as they get a kickback off of that rate.
Now, as far as your credit reporting goes, you are misinformed.
The credit impact of an inquiry is exactly the same wheter it is a prime lender or a sub-prime lender. There is no difference for scoring purposes on the inquiry.
It makes no difference how many lenders this dealership "shops" your application to. The impact on your credit score is the same whether it is 1 lender or 100 lenders.
Credit scoring on inquiries is done by type of tradeline.
In a 30-90 day period, depending on bureau, all inquiries created by you shopping for a car have only 1 impact on your score.
Now, if you also applied for a credit card, that would be an additional impact, and if you also applied for a mortgage, that would be an additional impact.
The bottom line is, that there is a reason you are being shopped around sub-prime lenders. Your credit sucks.