The burning leg problem is a BIG problem with the E450 in the south and west. They simply do not put enough insulation in the floor or the engine cover of the chassis.
We had a 99 Minnie Winnie and the floor was hot, the engine cover was hot and the wife was not happy. I pulled the front seats, pulled the carpet and installed a 3/8" thick foil backed fiber pad to the floor and the engine side of the engine cover. Took maybe 5 hours to do the whole thing and much better. The floor was barely warm and the engine cover was barely warm. Before the insulation, it was hot to the touch and uncomfortable.
If I was buying a new B or C, I'd insist the delaer install the insultion and safe myself the headache.
Amateur Radio Operator (KE5DFR)|Full-Time! - 2012 6.7L Ford Crew Cab Dually -2013 HitchHiker Champagne 38RLRSB - Travel with one Standard Schnauzer and one small Timneh African Gray Parrot