323i is a good choice.
Less stressed engine, less stressed driving, more comfy suspension.
The LCI E90 are quite reliable.
The usual checks.
Pull back the door seals to see signs of accident repair
Look at the paint from different angles to see if there is a slight change in colour compared to the other doors/panel. This can be a sign of accident repair
BMW Malaysia's has a really messed up service interval during the BSRI period. Sometime it says 20000 km, but some went as far as 25000km. This is the fastest way to kill an engine. Open the oil filler cap, shine a flashlight into it and check for sludge(Jelly). Run far far away if you see any. Best to buy a car from a buyer that services their car every 10000km regardless of whether its covered by BSRI or not.
Look for receipt that the gearbox oil has been changed. According to BMW Malaysia, it is maintenence free for the life of the car. Their idea of a car's lifetime is 100000 miles ( or thereabouts ), driven in Germany ( good weather, AutoBahn, much less traffic ). In Malaysia, it is completely opposite and an oil change is highly recommended at 40000-50000km interval.
Drive the car around and check for strange suspension sound. Malaysian roads are not too kind to our suspension arms and components. Slight sound can be tolerated but use this to negotiate some discounts to change the suspension arms/bushings.