In other Forzas, I believe FM6 and FH3, when you removed the 2008 Viper ACR wing, it’s top speed (correctly) increased from about 170-180mph to about 200-210mph (heavy downforce removed).
To clarify, this is when the spoiler remove/delete option is selected when upgrading the car (it comes stock with the big wing).
I think this is a bug that was missed and needs to be addressed.
Thanks!