Originally Posted By: btanchors
I have a 2003 GS 430. Same car, but with a 4.3 Liter V8 instead of a 6 cylinder engine and a few other options.
I have owned mine since new. A couple of things to look out for:
1) The door lock actuators are a common failure point. They also cost $500 - $600 to replace, on EACH door, if you do it at the dealer.
2) If your GS300 comes with the Mark Levinson audio system, the subwoofer blows easily. Most are already blown by now. It costs about $609 to replace at the dealer - the rear seat has to come out to get to it.
I have had two other failures on mine - the starter failed and had to be replaced. It's a pain on the V8 because the starter is actually UNDER the intake manifold! Obviously, this is something specific to the V8, not the 6 cylinder you have.
My motor mounts also failed - meaning the engine would actually LIFT up several inches when under load.
So that's a total of 4 significant items - sounds like a lot, but bear in mind my car is over 12 years old. It still drives great, and I still really enjoy this car. I plan to keep it for several more years.
FYI, You can DIY those door lock actuators for less $15 per door.