So this route is from my personal playthrough, I can't find a quicker route than this but if all done right then the game can be finished in less than 2:20 in Any%.

Compact: Interstate Loop - Race Silver Lake - Pursuit Interstate Loop - Road Rage Palm Bay Marina - Road Rage Airport Terminals 1 & 2 - Pursuit Silver Lake - Eliminator

Compact GP

Muscle: Airport Terminals 1 & 2 - Race Downtown - Road Rage Harbor Town - Eliminator Airport Terminals 1 & 2 - Road Rage Sunny Valley Downtown - Pursuit

Muscle GP

Coupe: Vineyard - Race Big Surf Shores - Road Rage Sunny Valley Downtown - Race Winter City - Eliminator Airport Terminal 3 - Face Off

Coupe GP

Sport: Sunrise Valley - Burning Lap Airport Terminal 3 - Race Dockside - Pursuit Interstate Loop - Road Rage Riviera - Road Rage Big Surf Shores - Face Off Winter City - Road Rage

Sport GP

Super: Golden City - Road Rage Dockside - Eliminator Winter City - Pursuit Interstate Loop - Race Dockside - Road Rage

Super GP