I've been looking at IROCs, specifically 1985-1989. I've looked at a lot of them online. I've actually looked at three different IROCs in person and have test driven two of the three. The third was a hard "No" so I didn't even test drive the car.

Whether seen online or in person, on the bottom side of the cars, I've noticed that some cars appear to have some body color over what looks to be gray primer. Mostly gray with some "body color overspray." Other cars appear to be black on the bottom. Both cars that I test drove had bottom sides painted black. I know for sure that one of the two had the floorpans replaced so that explains the black paint. The other car had some surface rust sanded down, sealed and then painted black. Other cars I've seen online also have bottom sides painted black.

I'm just trying to figure out if the black painted bottom sides indicate that some work was done to the bottom. In other words, not OEM. I'm 100% open to be educated on this. Thanks, everyone!

 

The only direct experience with a car that I know was original, had grey primer in a few spots that you could tell didn't fully get painted. It's a good question, and I don't have a definitive answer, but that's what I saw on that car. It was an 89.

BTW, Iroc was made up until '90. If you didn't know, then you're welcome. But if you DID know, but you don't care for the updgraded interior.....I say.....NICE ...I don't either, but I'd still drive one, haha! Anyhow, good luck with your search!

 

I'd suggest going through the History forum and looking for threads about auctions, open the links to the auctioned cars and look at their pictures. They're usually very low-mile all-original cars that haven't been altered, although some may or may not show signs of clay residue, and often there are pictures of the undersides.

 

 

This is the underside of an '89 IROC-Z with 436 miles, I was under the impression from the BaT ad that it was all original:



I would wager a guess that they looked mostly like that from the factory. I believe undercoating was a dealer option though.

 

I attend the one week long car show called "Cruzin' the Coast" on the gulf coast of Mississippi every October. Sunday to Sunday. This year they had over 10,000 registered, participating cars. My father-in-law lives there so it's a great visit for my wife and I. Cruizin' the Coast only allows cars 1989 and older. I just recently got my LS3/Tremec T56 Magnum swapped 1991 Foxbody coupe on the road. 25 Nov to be exact. Can't be a participant with this car at CTC.

 

I've looked at pictures of a lot of low mileage cars on eBay, Autotrader.com, Hemmings and Bring a Trailer. Some looked like the picture that Komet posted but others had black painted floorpans. I can check out the History forum and see. I still won't really know if the car bottom was OEM or modified.

 

I had been interested in a red IROC for sale on eBay that was red and it's bottom side looked like this car. The seller had it listed since about September. Interestingly enough, it was still on eBay this morning but then I got an email later saying the car was no longer available.

 

I am not 100% certain, but I believe I remember reading that the bottom side color is related to plant where the car was made. Mine is an 85 IROC made in Van Nuys and was all black underneath with no gray primer when I bought it. I am 100% certain this was original.

 

My '86 IROC, built in Norwood, and which I bought new, is gray primer underneath, with a lot of base-coat overspray.

 

Awesome information, guys! I just assumed that the black painted bottom cars had been modified and now I know that is not true and that the car might've been a Van Nuys car. Just awesome information from both of you.

 

You can tell which plant the car was made by looking at the VIN. If the 11th digit is an "L" it is a Van Nuys car. If it is an "N" it is a Norwood car. Be careful, as I am still not sure this is absolutely conclusive only some observations. Mine is a black car. The underside was all a satin black even above the gas tank with some gloss overspray around the perimeter. I found this out after cleaning off the original dealer applied undercoating.

 

Ok. It looks like we still need someone else to confirm whether or not an original, OEM, Van Nuys IROC had a black painted bottom from the factory.