Simple. Peace of Mind.
Not every Dealership, small or large, will be honest about the condition of a vehicle, most large dealership have guidelines as to what a vehicle should be for "Safe" driving, example if the brake pad has at least 50% of life left then they are deemed "Good". 50% life on brakes, depending on your driving conditions, could cost you a brake job by the 1st year of ownership. The same thing applies to Brake Fluid Flush, Coolant Flush and especially Transmission Fluid unless you know how the vehicle was driven, normal speeds and long drives or fast and aggressive in heavy stop and go traffic, you may end up responsible for transmission due to early deterioration.
The disclosure "AS IS" means either the price was lowered to minimum profit or negative profit (that can be a red flag!) or there’s a problem/problems with the car. If they do not offer you a warranty, there’s a good chance they may be hiding something. If they are reputable dealership and are doing their due diligence with each car assuring they are in good and safe driving conditions, they will offer a warranty and let you take it to your shop of choice for a pre-purchase inspection, simple as that.
Here is an example of a first time customer that came into our shop:
He brought his daughter’s 2007 Audi A4 after researching USP Euro Car Care on Google. His complaint was that since they purchased the vehicle a month ago the battery kept dying, he also told us that the fans never turned off. When the technician diagnosed the vehicle he immediately noticed wiring problems with the condenser fans, wires spliced and exposed making this vehicle a dangerous situation. We proceeded to check the relays and noticed that the ECM (Engine Control Module) was new, when lifting the ECM he found stagnant and contaminated water covering all the relay boxes including the area missing the relay for the fans. We also noticed that the cover was damaged and water was trickling into the driver side interior were the carpet in the front and rear were soaking wet and the power windows and interior lights were shorted.
This was a terrible situation; the vehicle had water damage and having to explain to a new customer that the vehicle they purchased for their daughter needed thousands of dollars’ worth of electrical work was not an easy conversation. At the end, the customer was grateful that we had pointed out all the issues the vehicle had including oil leaks. We didn't sell him on any repairs and better advised him that he find out what recourses were available to request that the dealership take back the vehicle.
A pre-purchase inspection can save you hundreds or even thousands of dollars not even counting the headache of dealing with the aftermath of a bad deal. Think about the pre-purchase inspection fee as insurance on your vehicle investment. Peace of Mind!