If the receipt is written out properly by the dealer there will be effectively no warranty.
I would assume for something like the car Allon White had for sale recently with a cracked chassis that it would say that the car needs extensive repairs s and a replacement chassis before it be considered roadworthy. You would have absolutely no hope of enforcing a warranty claim.
On the other hand if bought from a less scrupulous dealer who didn’t mention the cracks & it failed an MOT on it next week, you would have some recourse. There is also the price to consider, if sold at market price for a perfect car that would be taken into consideration.
As a buyer to protect yourself on some thing like the AW car you would want the receipt to say engine in good working order etc so that if it isn’t you have some recourse.