That's how black cell had it in old renegade. You as a player rank up. Veteran, elite, and legendary.
Requiring 1200, 2000, and 4000 points respectively. Also had vet points which vary based on what you do. Ie: repair, kill units (each gives dif vet PTs), disarm beacons, kill buildings etc.
I'd raise the points to like 3,6 and 9k points or something. The bonus varies per vehicle. While chem troopers might have 180 health and armor at legendary vs 150. Havocs had 312 health and 120 armor or something.
Legendary vehs auto healed about as fast as mammys do. Light vehicles were given medium armor when legendary. (Artys armor acted like stanks, havocs were weaker).
It was fun, gave players something to work for. It was my favorite server side mod on any server in renegade.