I bought the 2006 GS300, I opted for the AWD, a big plus in rainy
weather and it corners like a Formula One, got the sunroof, also very
nice, wished I had a little more power, ergo the 350 would be a better
choice, got the adaptive headlights and headlight washers, that's not
important, no Mark Levinson, and no Navigation... I understand you can
get navigation now, my advice don't get it, for about $350 US you can
get yourself a humdinger by Garmin or Tom Tom or Magellan, that beats
the pants out of any lexus developed navigation... may not look pretty
sitting on your dash , but its versatility and eye level location more
than make up for it.
PS save some money too, it runs great on regular gas (recommended by a
Maryland dealership), also the AWD has a footprint in the driver's
footwell, does not bother the driving, but it is hell to find rubber
mats for it..... good luck and enjoy, also the Lexus is pure luxury
driving, but if you want pure driving pleasure, opt for an Audi A4
with AWD instead.