i sold personally before, so many hassle and troublesome buyer.

buyer appoint to test drive, come visit, come late, didnt make it, last minute change mind, all sort of weird reasons while i already make up my own time but buyer put aeroplane.

then when all is fixed, need to find a runner to do all the jpj form tests, fingerprint transfername.
queue jpj to test the car. gosh hassle.

and moneywise is another thing, buyer dont dare to pay first before name transfer and i dont dare to transfer name before payment.

when selling just giv you keys to them, they need to take your car to jpj to do tests. they will issue you a receipt after taking your car.

when buying, normally i pay deposit, then when name transfer is done then pay the balance. these all agreement depends on you both,
if you buy form a reputable 2nd hand dealer like in a whole big center full of 2nd hand dealer they wont run, they got a shop there and normally is their sales rep deal with you and not the boss. not to mention they got much more pricy car like bmw and merc in their porch, not worth to scam.

if you deal with a weird guy side of the road or something then avoid it.

but my opinion this is not something i worried about, the car condition is what i worried about, lets say the engine / transmission failure after 2 weeks or 1 month of driving, and those shop claims they have 1 year warranty, it will be a mess and pushing here and there unless you got a 3rd party engine/transmission insurance warranty.