Car Dealerships and the rustbuckets in the back

I was wondering. i heard from the famous Davidsfarm on youtube that he had gotten free cars from the back lots of car dealerships.
i.e rusty ones in the back that people traded in for money off of their vehicles.
My question is: Is that very information true?
and this is were i was inspired to look for this information

Ahh theres the video…Anywho…Most dealerships that I have seen around here used to have the “Saturday Special” Would be around 100 to 500 Bucks…I really dont think You’d get a deal at any of the dealerships in town.

My experience is they won’t sell you a rustbucket due to liability. 

No Its not liability, I seen some pretty rough vehicles in some dealerships, “As Is where is” is stated over and over again with a statement of “No Warranty” Most dealerships will sell ANYTHING to make a buck, But there are some that don’t want to sell rusty crap used cars because of reputation.