[2fast4u]

i would say to buy a used car u certainly need to have some skill level with a very good eye for detail exterior interior and a very nice ear when u have the engine started.

once exterior interior is fine to ur liking then

first thing in engine bay area is the appearance of the engine itself,
check for leaks on the head gasket area, check the filter,
open the oil cap and inspect oil cap it tells a lot - the cap and the sight of the rocker,
open up a plug and u know what is engine performance level and it can tell u many things,
idle engine sound can interpret many details and when throttled exhaust can tell you alot more.
the test ride according to me should be like a rally driver with sharp lefts and rights and that will help you in knowing how good the suspension system bushings, ball joints, steering response are.
there is a lot of things to say but these are some basics,

Yes have to agree a new car has all the stuff and gizmos but after 3 yrs of warranty it is a real pain when you come to know how some electrical failures or some auto mechanisms going off without warning.

My colleagues Renault Laguna 3.3yrs old had a problem with the auto lock mechanism in which the One Rear door would remain open and when taken to dealer it was found the Block mechanism is kaput a replacement was BD110 = 12K Irs approx.

There are Cons and Pros in both segments whether New or Old but it finally all depends on your budget

With a cash strapped budget of 5 lac if someone bought a Getz rather than a W124 thats a rational buy but if someone still bought a W124 then he sure is an motoring fan.

ps when i bought my car (UAE) 5 yrs back it had 135k when i was getting it transferred to Bahrain i met the owner by chance at the Traffic Dept and he mentioned the car had over 700K when he was first owner and so he reset meter to 90K.
So buying a used car you will never know the exact mileage. For me Id say it was sheer luck to get a marvel of an engine.