i) engine
- check for leaks at either underneath the engine, the engine head area, rocker cover, fuel injector, intake manifold, exhaust manifold, crankshaft, camshaft, etc... check if there are engine oil or fuel leaks..
- start engine and listen for funny noises, rattle, vibrations (if more than normal), tappet sounds.
- see the timing belt or the other belts needs to be replaced.
- see if got any white smoke from exhaust

ii) gearbox and drivetrain - clutch, gears, driveshaft
- see if engage gear easily, or there's a jerk.
- drive car and feel the gearbox and also listen to funny noises..
- check driveshaft. see and feel if DS bengkok or the DS boot is koyak.

iii) cooling system - radiator, waterpump, thermostat
- check radiator for leaks, check hoses for leaks or signs of hardening or rusts.
- drive car in traffic jam or high speed or high incline (panjat bukit), and see if the temperature rises.

iv) turbo
- listen to it spooling and listen to funny noises.
- drive hard (masuk boost) and see if the car go or not.
- press accelerator pedal and see any bluish silver smoke from exhaust.
- if got boost meter, see if got any boost spike or boost creep; while driving on boost.

v) chassis
- check for signs of accidents. from engine bay or boot, u can see if there are any signs of ketuk body or maybe sometimes u can see the sign of cement..
- check the pillars ( pillars A,B and C). take out the door rubber and see for sign of welding or sambung or cement..

vi) suspension system
- look underneath the car and see all the lower arms and upper arms. look at the bushings and balljoints.
- look at he suspension for any leaks from the absorber.

well, that's what i can think of rite now..
and always ask to test drive the car. no test drive, leave it..