The only serious problem I have had with the car is; the radiator pipes cracked, the engine overheated and the head gasket cracked. $850.
Other problems:
Driver'as side door electric window motor needed replacing - $50.
Boot button stopped working, $5 for wiring.
Rust on the rear window seal, was very difficult to fix. Needed to dismantle the rear window fitting, putty over small rust holes, sand and reassemble.
Beast of a car. Drops standstills very easy.
I have worked it a bit. B&M stage 2 shiftkit, genie extractors, 2 1/2" exhaust, 9" 4.11 diff, light weight drive shaft. Also bonnet scoop onto big carb. VX SS 17" rims, 2 pac 2 tone brown and silver with chrome trim. Monster taco, VK console and dash, SL/E interior.
Also Pioneer head set, Kenwood 4ch 1000wt amp, 12" sub behind back seat, 2x 300wt 6x9" & 2x 160wt 6".
Does your Commodore have a speedo that goes to 265km/h?