I've got a '93 Excel (bought new). About the only major problem happened when it was about a year old - had to get a Ford van removed from the trunk (interesting that the other collision experience mentioned here also involved a Ford). There were a number of minor issues, and dealership mechanics don't seem to be very good at diagnosis (couldn't track down an intermittent "click" when stepping on the clutch - I found a cotter pin that occasionally hung up on the brake pedal, and installed a dashboard clock so it dimmed when I stepped on the clutch - couldn't see that they were working with a mirror-image wiring diagram because the "wrong" side of the connector was easier to get at, and the "dimmer" line should have gone to the headlight switch). Get a decent independent mechanic and you shouldn't have any problems.
Check out the Toronto Star "Wheels" section from May 14th (page G16) - the used-car feature in that issue deals with the Santa Fe. They missed a problem with the tailgate (I measured one at the auto show), which has an opening 47 1/2 inches wide (the "U" in "SUV" is supposed to be "utility", and sheet goods are 48 inches wide), and they say that clutches don't last very long. Personally, I can't tell you how long Hyundai clutches last - my car is still on the original.
One thing to watch out for is that the dealer chain (in Canada, at least) discontinues touch-up paint 2 years after the colour is no longer used on new vehicles. That's about the time when you start needing it on a regular basis (stone chips, etc.).