It's time to do some more reading. There were '90 model year IROCs. The IROC name was taken from the IROC racing series and in 1990 Chevy lost the "contract" to have thier cars as the IROC cars. Dodge won the contract with thier superbly awsome Daytona

. The "contract" on the IROC name ended December 31st of 1989. If you check into it, most car manufacturers start producing the next model year in or around August of the year before the "production year". That's nearly 4 months of cars built as IROCs under the Camaro name. It's not a HUGE number of cars, but they are out there.
Now on to a better question..... Why not just go with the '91-'92? The IROC package was really nothing more than an appearance package (aka stickers and stripes) on a nicely equiped Z28. Besides, the 91-92 cars have nicer dashes and better ground effects and rear spoilers. That would satisfy your parents needs for WORKING airbags and you would have a nice car......Mines for sale