Rear gets loose if you apply too much power exiting a turn. In 500PP Classic Muscle Car Challenge, placed: 2nd at Mazda Laguna Seca, 3rd at Madrid Reverse (would've been 2nd except for stupid mistake on final turn), 1st at Daytona Speedway.
Specs are with fresh engine (just rebuilt with no wear). Chassis not rebuilt, probably should be. This setup needs work but it's a start.
I wish GT5 had wear/damage indicators for engine and chassis so we'd know the right time to spend all that money!