Ford Thunderbirds were raising a stir in Nascar and the folks at GM didn't like it. The curvy body and slightly-bubbled rear window of the 'Bird was making it more than competitive, especially at the Superspeedways. The answer was to modify the Monte Carlo, and Grand Prix with VERY-bubbled rear window, and produce a certain amount for the public, for homologation. What ensued was an exciting time in Nascar and produced some fun street cars.
The Monte was open box when I bought it and took about two years to piece it together thanks to a couple good folks here, thank you. The 'Bird depicted is the '87 Turbo Coupe. Both Revell/Monogram. So not to clutter too much more photos of each in my Fotki.