Yes, it's much less expensive to learn as much as you can about a car *before* you buy it :_> Your friend got screwed with the tires. If they were defective when delivered on the new car then the dealer should have replaced them free. Don't buy any dealer-applied junk such as paint or fabric protection. It's a complete waste of money.
Car manufacturers have three criteria for tires: Cheap, round & black--two of those are negotiable. Yes, I run 45psi in my tires. Many believe that is soft. Higher pressure increases tread life & fuel economy. This is the VentureShield website: VentureShield. It is a plastic film applied like a decal. The site has a list of installers by state. A dealer will just subcontract the work & charge more. I seem to remember a recommendation from Texas so I don't think climate is an issue. The primer is white & the paint scratches easily. www.carbuyingtips.com sates that the sale of your car & the purchase of the new one are two seperate transactions. Chances are that if they are combined the buyer will get screwed on the price of the new car and the value of the trade. Ask your DMV how to transfer the registration & plates and the fees. Dealers are notorious for inflating or creating state fees and taxes. TP sensor Let's say the tires are at 40psi. By pushing the button on the dash the sensors are programmed to recognize this as the standard pressure. If a tire loses 25% (10psi) the sensor will activate the warning light. Next we adjust the tp to 32psi but don't push the button to reset the sensors. Whenever the tire loses 2psi the sensor trips. Adding more than 2psi turns off the light but not for long as such small variations probably occur weekly. For quite some time buying the car at MSRP was the only deal in town. In this market I would think that is high. Best wishes for finding what you want at a good price.