I'm planning an arcade mode speedrun and this has confounded me for a while, but I finally have it figured out.
Races must be completed in normal OR difficult mode and in each car class (A,B,C) to unlock anything.
Winning high speed ring unlocks autumn ring
Winning trial mountain unlocks deep forest
Winning GV east unlocks SSR5
Winning Clubman R5 unlocks grand valley
When any of those 4 pairs of tracks are fully won (both with A B and C cars) you unlock a new dealership. The dealerships will go in the following order (at least for NTSC US)---Toyota, Suburu, Dodge, TVR.
Side fact: I also discovered that the WRX is faster than the old Chevy and all the other originally available cars, it's grip is unreal. The vipers seems slightly faster, and I haven't tested the TVRs because once you have them, the run is over.
Hope this helps!
Races must be completed in normal OR difficult mode and in each car class (A,B,C) to unlock anything.
Winning high speed ring unlocks autumn ring
Winning trial mountain unlocks deep forest
Winning GV east unlocks SSR5
Winning Clubman R5 unlocks grand valley
When any of those 4 pairs of tracks are fully won (both with A B and C cars) you unlock a new dealership. The dealerships will go in the following order (at least for NTSC US)---Toyota, Suburu, Dodge, TVR.
Side fact: I also discovered that the WRX is faster than the old Chevy and all the other originally available cars, it's grip is unreal. The vipers seems slightly faster, and I haven't tested the TVRs because once you have them, the run is over.
Hope this helps!