TT-01 are a good drift car and easy to look after.. couple of minor hop-ups.
Like Inc0321 said.. bearings, alu drive shaft and maybe a better motor, although the sports tuned motors go alright and donít need maintenance.
Also look at a damper hop-up i think the stocko ones are a little average.
The Losi Drift-R would'nt be a bad buy.. being a XXX-S the belt is sealed which is good for car park bashing. Also bearings and decent dampers are included. Also u get a basic novak speedy which can handle down to 15t mod when u wana upgrade the motor, a Trinity 19t motor.. which are ok but i dont think they are top notch trinity and a JR radio.