The primary rule of vehicular combat is: You can always ram.
When all else fails, when the weapon systems are offline, when the computer is dead, when the engine is half-crippled, as long as you can move at all, you can still heave about and crash into your opponent.
In fact, even if your vehicle is totally immobile, a suitably clever player will still find a way to ram it into an enemy vessel.
R2-D2: All right, if we don't have thermal fusion shock-lances, I'll just use metal-eating nanite bombs with our mass-driver.
GM: You don't have those either.
R2-D2: Gravity wave implosion field?
R2-D2: Zero-point energy inverter beam?
GM: I don't think so.
R2-D2: Allotropic iron torpedoes?
GM: Let me check....
R2-D2: How about a trebuchet?
GM: You have laser cannons.
R2-D2: Okay, I can work with that. It's not the power of the weapon, it's what you do with it. Firing pattern: Delta!
R2-D2: 1. Well that's the last daylight that die will ever see.
GM: You missed everything in the entire battle.
Obi-Wan: What are the odds of that, R2?
R2-D2: Ramming speed.