Folks, check out
autorust.com - Makers of the Frame Saving Safe-T-Cap Kit I'm in Cranston, RI. Went to them for a quote last year on rust-proofing my 2011 4R. It's a California car, so I'm lucky there's hardly any rust. However, they only have one service level - $1,500 to sand-blast your frame, floor, etc then spray with some undercoat.
It was too expensive and time-consuming for me, so I passed up on them. This year I'm opting for a simple fluid film spray-on in a couple of weeks.