Orange/brown paint in trunk?


New Member
Good morning, folks. First post, fresh off of buying a great “barn find.” 87 Grand National, 5051 documented miles, has been sitting in a climate controlled garage for 10 years.

I’m going through the car making a list of parts to refresh her, and I notice in the trunk by the wheel well an orange-ish brown paint or finish. The current owner claimed it was a dealer undercoat/rust prevention but I can’t find any pictures of this same thing.

Does anyone have orange/brown in their trunk? Or did I get swindled and this is hiding bodywork. My mechanic and I went around the car and it’s all original seams, all steel, takes a magnet… so not sure what’s going on here.

Thank you for the help!
Ah that’s fair. There are still boxes and spare parts in the trunk so forgive the picture quality. I’m looking further it seems to be on every seam in the trunk and on the inner quarter panel itself on both sides, there’s no textured black paint underneath. It’s also slightly tacky and can be scraped off. Could it be a true spray on rust preventative?




Having a litttle trouble with photo size.
Yeah it’s strange stuff. Car doesn’t have any other indication of an accident or body work. I guess I’d be curious if everyone’s trunk has that texture black finish all the way to the seams, or it it stops about an inch from the top of the sides and far back behind the wheel well. If so, this could really be some dealer applied gimmick as the previous owner said. That or I really got taken.
I have some brown gooey stuff on the inside of my trunk lid, inner fenders from and rear on my 86 GN. The 87 doesn't have it, I assumed it was some sort of rust preventive.

Mine is soft and can be easially scraped off with a plastic scraper.

That’s excellent info, thank you. Yeah, this seems to be the same just another color. It’s very sticky, can scrape off with a fingernail. Just wasn’t sure if I should be worried about the fact it’s over raw metal but it seems from those photos you have raw metal in areas as well.
If your concerned about keeping it in its current state this may not he a good idea. If not but maybe find an area that you can clean off to ensure the inner body panel is uniform under that stuff. It would help prove its not shotty body work and likely some dealer gimmick rust proofing.

All mine is in easially accessed areas like the trunk and inner fenders where they had easy access in front of the front tire from below the vehicle.
My current or previous Buick turbo cars have not had that substance. The copper color is odd what ever it actually is.
My guess is a cavity wax product due the ability to scrap it off? I would bet it is in your lower door panels also? Local friend was a GM tech back in the 80,90's, says that was a dealer item that was sold to new car buyers. Kind of like Scotch guard for you old guys.
Yes, I have seen dealers apply copper gasket spray (a real thing) and sell it as a rust preventative. Could be like that. Normally just an "up" for a "lay down" customer (real dealer talk!).

It was the eighties. Loads of things were revenue streams.

That yellow stuff from @mblum looks to be "Rusty Jones" which was a popular add on as well.
Friends, I really appreciate the help here. Lines up with what the seller said, and matches what you’re describing. Certainly puts my mind at ease. Now for the real work before it gets warm enough to drive her!
Years ago Shops started using LPS 3 as an undercoating on new cars . I remember my dad showing me how they applied it with a spray gun and it was / is brown and it " dried " to a tacky texture .
Years ago Shops started using LPS 3 as an undercoating on new cars . I remember my dad showing me how they applied it with a spray gun and it was / is brown and it " dried " to a tacky texture .
LPS3 dries somewhat clear with a wax consistency. I use it all the time for the salt up here in NY. Good stuff