My Svt has 125K miles. I've replaced the Cat, and the water pump.
The Cat problems came from my 1st CE light. That light was for a bad plug wire, but I negligently drove with that light on for about 3k miles. When I had the wire repaired, a week later I had another light for a bad Cat.(I think I was dumping raw gas into the exhaust) Luckily for me, it was at 49,950 miles, so the Cat was replaced for free.(WHEW)
I had the water pump replaced at the 100k tune up. My car never ran hot, despite plenty of city driving. I think they just wanted to replace it because they new it was just a matter of time. The problem is that Ford, in an act of complete stupidity, made the vanes on the water pump out of plastic instead of metal. So those things DONT LAST.
I've been lucky, because even though my car hasnt been perfect, the dealer hasnt charged me for the 'diagnostic fee' of just hooking it up to the computer. They just charged me for the work, so my plug wire was less than $50 bucks.
I've priced Lexus IS's lately, and I like em, (despite the fact that an E1 will smoke it) but I just cant by a car from Japan. What can I say...I'm a patriot.