Hmmm... no - that's news to me. When I was in living in Toronto and racing with the local F-body (Camaro/Firebird) club (because they'd set courses that fit larger cars) one member did occasionally race an SRT8 Magnum. That was a sight to see. Much like drag racing, there is a wide spectrum of driver talent out there in autocross and the driver mod tends to be the defining factor not the car (Hell, I've been out run by a stock Yaris on a tire).
Most people don't realize that these cars underwent a massive suspension revision in 2015, and how much it contributed to serious gains in handling and suspension dynamics. They just see the dumpy '08-14 cars out there still. I think I am going to surprise some people this Summer.