Tips on Buying Cars: Certified pre-own program and program vehicle, bill of sale, salesperson

Question
When I am purchasing a auto with the certified pre-own program or program vehicle and finalising the transaction with the salemen, are there some things I should keep in mind to keep cost down and to protect myself?

Thanks in advance.
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Answer
Hi sallie
When you have settled on a price with the salesperson at a dealership...then its time to go to the business office to get your bill of sale...there you will be offered ext warranty along with rust-proofing- life ins-perma shine and anything else they may have to offer...its going to be your decision as to what you may need...
you want to keep your cost down, then dont buy anything...
Regards
 Ray
PS
If i am reading your Q right, then above is the answer...if not then explain in more detail what your trying to say