I feel like this would be a neat addition. When GR has this modifier it would randomly select few vehicles from each spec in the route(5-10 vehicles) and players can choose only from those. It would roll the vehicles server side globally for when that modifier occurs(everytime GR rotation with this modifier would come it would do this roll) or it would be lobby based so each lobby would have its own roll. All the vehicles would be loaned during this modifier.
Example:
Route: ST1 > ST2 > Hypercar
Random roll for ST1:
Mustang Boss Lime Ed.
Audi RS2 Avant
Nissan 300ZX
Plymouth Road Runner
Chevrolet Corvette Grand Sport
Random roll for ST2:
Chrysler 300
Lamborghini Diablo
Audi RS5 Sportback
BMW M5 CS
Porsche 911 RS3
Random roll for HC:
Lamborghini Revuelto
W Motors Lykan
Porsche Carrera GT
Bugatti Chiron
Koenigsegg Gemera
This would honestly breath a fresh air and would incentivize to use other cars than meta(obviously even within these there would be a meta) but it would change things up
