Depends on the model. JDM versions are slightly different than American market(GS300/400). I know the V300 is a twin turbo and very cool. Basically, if it is the gte (turbo model) you will want to look for smoke out of the tail pipes indicating burning fluids. It may be as simple as turbo oil seals or worn valve guides. Possibly head gasket. Check electrical functions. The JDM's had a unique digital screen gauge system that acts up too. Other than that, some typical problems are starter contacts wich are very easy to fix. Door sagging - loose hinges indicated by small dent or wear in the door jam area. Of course you will want to look it over well and check for oil on the ground, fuel leaks, coolant leaks - if it is the 4 liter the same issues can apply but different locations on the motor. Good luck - sweet car.