To repair a piece of equipment that is fairly new, and has the correspondingly large parts stock in the system (such as the LAV III) is easy shmeasy. According to sources closer to the ground than I (fellow grease-monkeys), G Wagon parts are also in good supply. Bits and grapple grommets are very rarely a problem. Turret baskets, grenade launchers, even barrels or entire actions, mirrors, lights (etc.) are all relatively easy to get and in stock.
The problem is, just like George says, that once a vehicle (say a sparkly new G Wagon) sustains a major bit of damage to the framing or body, there is bugger-all the various mechs can do (I know many genius Mat Techs, but it is difficult to weld together charred scrap) and there is currently, that I know of, no system in place to replace that vehicle. It gets removed from Plan Ex and the FMS, and no longer exists. It will just sit out back and slowly get stripped of parts ...I mean the damage report may change over time as more defects are found ;D That may not be a problem now, but in 5-10 years (or sooner, depending on how many take a beating) the strain on the fleet will be huge and the powers that be will have to start reallocating vehicles, CF wide.
And when I'm the lucky dog being the "young" TO in 1 Special Viper Commando telling the CO that we just don't have a G Wagon for him and the DCO to tool around in on EX (being hard-core, of course, as only the SVC BN's can be) because too many got blowed up across the water (or Wainwright, whichever applies), I'm not going to be having a good day.