it is possible i suppose...
my 1995 Ford Contour had 384,990 miles on it when i crashed it. the damned thing must have been a freak or something, cause it STILL runs like the day it was new, minus a radiator, a/c system and power steering.(due to the crash) as a result, i can only run it for a few minutes at a time. ..BUT...if a ford can make it that far, a toyota better make it farther.
BTW...
If i were you, i would switch to synthetic motor oil to get the most life out of your engine, also switch to synthetic tranny fluid as well.
but...my next door neighbor has a 2004 VW golf, and it has 67,000 miles on it already (he runs his own courier business). so no, i dont think its possible to drive a car too much. understand that every part on a car is a wear item, some things just take longer than others to wear out (I.E. rod bearings Vs Spark Plugs).
just a thought. highway miles are easy on engines and trannies, i think you will be fine for many years tocome if you stick to the freeways...how many miles do you have so far???