Going to order some undercoating from Resto Rick and was just wondering how much undercoating it would take to completely do the underneath of my car.I think someone said it comes in 1 gallon jugs,thanks.

Your going to use 1 gallon just in the wheelwells. My first guess was 4 gallons total.

Used a whole can to cover the quarters inside the trunk, and both the rear wheelwells. I still need to get another can for the front wheelwells.

You'll use at least 3 gallons.

It also depends how thick & textured you're trying to get.
I typically use about 2 gallons in the wheelwells & another 2 on a full undercoat car.
I also have the advantage of being able to walk over the shelf and grab another gallon.

Undercoating