On the fence on the extended warranty thing.....
My Experience - 1997 Mustang Cobra, took the warranty. Had a couple rear seals go (one of which took the whole rear end- didn't notice it until it was singing like a Church Choir) and a sensor and a few other things - I think I made out on the rear alone.
1998 Escort (wife's) - tranny was shifting weird and the dealer replaced something - next thing we know the thing was slipping and such. New tranny. I think it helped there as well.
2000 Explorer - no extended warranty. By 58k the tranny was toast, by 60k the engine was rattling cold. $2k + later I kicked myself for not getting it. The engine rattling was a known problem with that SOHC engine.
2003 Escape - extended warranty - oil pan gasket and A/C compressor all paid for by the warranty
2004 Infiniti G35 - no warranty. at 68k, the AC stopped working. $1300 and a new condenser, AC line, and Body Control Module later I had A/C. at 80k I may be looking at an intermittent MAF issue ($300 for the sensor alone). Wish I had the warranty.
I maintain all my cars well - by the books, oil @ 3k, follow the maintenance schedule and there have been issues. When I didn't have the warranty, I wished I had it and when I had it I didn't worry. Probably worked about even.....