I drove my old '90 NA across country and back: Pittsburgh to L.A., L.A. to San Francisco, S.F. back to L.A. then back to Pittsburgh in 1997. I find the FC is really very comfortable on long drives, but unlike more modern cars, there isn't much adjustability in the seating position, so if it doesn't fit you, forget it.

I do second what jackhild59 said earlier about the rubber parts; I think you'd be nuts to attempt such a drive unless you knew all your hoses, belts and seals had been replaced sometime in the past few years. Who wants to blow a heater hose somewhere in the middle of nowhere 2000 miles from home?

 

I've made several 3000+ mile trips in my 91 NA, all without incident.
Seems like the highway is it's natural element and compared to my previous car, a 1971 240Z, the 7 is a luxo-barge.

I think the biggest problem with the RX as a long distance tourer is the seats, I tried three different sets- including the rake and lumbar adjustable kind- before giving up and going aftermarket. The Mazda seats just hit me wrong and I couldn't stay comfy for more than a few hours.
The best OEM seats I ever had were from a Honda CRX (made by Recaro, I believe) and I tried a set in my 7 but they were difficult to mount with sliders and the lack of adjustment was ultimately a deal breaker.
Currently using Corbeaus but haven't done more than 300 miles at a time with them.

 

I would if all the maintance was kept up. Most of the stupid stuff that happens to me i fix on the side of the road anyway. Just bring some coolant, quart of oil(check every gas stop), belts, sparkplugs, and some tools(including tape) pretty much the typical stuff i carried around in my bins lol.

 

I drove from Atlanta to the keys 12 hours straight in my T2 without a problem.... well gas mileage was a problem hahah. Then I drove up to Sebring, then back to Atlanta. I ran so rich the entire backside of the car was covered in soot. It was only a few weeks later I was having some fun when I evaporated all my coolant. Turns out I left out the o-rings on the LIM so it was just the paper gasket holding all that coolant going to the turbo back. Just do a tune up and make sure everything is running proper before you go on the trip and you will be fine. Also helps not to beat on it along the way-- the less you drive it hard the longer it will last without something coming apart.