Your wrong there. The factory undercoating was put on thick, real thick. Not 1 car will look the same because they didn't care back then. As long as the car got covered they didn't care what it looked like. Like I've said I've scraped off a bunch of factory J55 cars and the results are not consistent. The stuff today is still not like the Undercoating they had back then. Try to duplicate this first pic of factory undercoating. I don't know what kind of junk bedliner you were using but it's obviously not the same what I use and doesn't look like plastic lmao. I've got some old pics somewhere if I can get them to download I'll post them. I done the 2nd pic about 4 years ago and in person everybody loved it and they even loved the Hippo liner I sprayed last year even better but I can't get those pics to download. Like I said If your driving the car use Bedliner unless you want to use undercoating and you like the dirt look that sticks to it but your restoring one correct and is a trailer queen I'd use the undercoating.

Even if you drive a car, good epoxy and factory style primer looking paint hold will up perfectly fine unless you think your driving the general lee and driving through gravel and off roading. New cars aren't even undercoated... my 230k mile 2001 truck still has primer on the underide and it's driven year round, mud/gravel, snow/salt etc.

There's no need for either other than the wheel wells and inner quarters unless you want to cover up flaws.

And I repeat, use bedliner on a car and see how people react when you go to sell it... if it's a valuable car, good luck! There's no need for it and no place for it on a muscle car.

I like Ricks stuff and have used the 3m stuff as well, both with no issues. I do use a 3m gun and keep it meticulously clean as undercoating sets up fast. As noted, air pressure and volume play a big role.

This right here is just frigging hilarious. I've worked from Washington, PA to Philly and all over Ohio the past 20 years. I know what gravel Roads which is Limestone and Salt and Calcium Choride does to your car. I've watched 2 Dodge trucks a Ford and Chevy just Rot away. I've used Undercoating on all my hunting rigs in the past and I love the dirty gray look it leaves when you try and clean it up lol. If I had a trailer queen or live in Miami Beach or Southern Cal I wouldn't use either but I drive my cars. So after reading your hilarious comment I'm done with this post.

You seem to think you know more than you actually do... all the rams you see rust out in the wheel wells for example is because they trapped dirt/junk between the wheel house and bed side. Nothing undercoat or bedliner will change... goes the same for gm and fords. No under coat or bedliner is going to be able to get into this area. In fact it would just help trap it more than just pressure washing it now and then. Your not bedlining inside the frame, body mount areas etc. If you want to avoid rust out, your better off spraying oil on them.

230k and northeast 4x4 driven winter/gravel etc and yet my trucks not rusted out underneath... explain that keyboard pro! Go lay some more pipe, you obviously have no idea what your talking about.