Need some Opinions
 

I am looking at buying an 05 RX gt with only 7,600 miles on it. I test drove it a couple of days ago and was VERY impressed. Are there any reasons for me to not look at an 05, and try and find an 06 with more miles?

no.

nope

In a word, no. The general consensus here, at least, is that by the '05 model year most of the new model "teething problems" had been resolved. It's the '04 model you might want to be a little more wary of, but I suspect ANY year RX-8 would be ok provided you have all the flashes and the couple of recalls done. The important one is the bigger battery/starter motor recall that largely solved the flooding issue. The '05 you're considering should already have those.

Thanks for the input. Another question....this car is missing a spare in the trunk. Is this a standard, or is the spare an option?

the spare is an option. you can usually find people on here selling the spare and mounting kit for $200-$250.