Dude, either your BS'n everyone here or your parents are complete idiot's. Which is it?
I'm not trying to be disrepectful. Just pull the trigger and buy the car or don't buy it.
The remark you made about the history of the car being bad is a load.
If the money to buy the car is coming from your parents then you are at their mercy. If they are so naive to think that an SC400 is a piece of bad merchandise they are out of their minds. Not only that, but if i were you, I would be very skeptical of any advise they give you in the future. I freakin' hate it when people (parent's or otherwise) spew crap out their mouths just because they think they need to give advise. As they say "The road to hell is paved with good intentions".
Sorry about the rant. Look, if your parents are so concerned about buying a Lexus, just tell 'em to forget about it and and go out and buy you some piece of crap like a Cadillac or Daimler Chrysler.