I just got a dealie in the mail from the dealer I bought the GTO from saying I should bring the car in for it's 3000 mile service and oil change. I was under the impression that the computer would tell you when the oil needed to be changed. Am I crazy? Should I do it at 3000 miles or wait until 5000?

3k vs 5k service intervals...depends on how your goat is driven. What % of the time are you on the highway vs. city driving? If you live in a harsh climate (excessive hot or cold, do frequent stop n go, or if you often don't get to up operating temp) I'd suggest the 3k service schedule. If none of these apply, you're fine with a 5k interval.

FYI-I have several test vehicles with 100k+ miles, serviced every 6k (using conventional GF3 oils) and all are clean as new, internally speaking. The fleet runs approx 70% highway, 25% city, 5% gravel.