I just bought a new white xterra and have a question.If it is not mentioned on the sticker do I have clearcoat? like is it an automatic thing you get? reason for asking is that the finish seems to be less glassy than I think it should be for a new car.Also water does not bead up at all. If it has no clearcoat would it be a good idea to get one put on? has anyone else done this?
Thanks.

I would try giving it a good coat of wax. My truck looks dull and the water doesn't bead when it hasn't had a good waxing in a while.

Learn from my experience. I bought a new 2002 X in early 2003 and it had been sitting at the dealer quite a while. Had the same issue as you described and I tried many different waxes and such to get the paint to look right with no luck.

I recently posted about it here and a local XOC'er came over with his orbital buffer and some good polish and the paint literally looks way better than new.

But...since you just bought yours, go to the dealer and tell them you want it polished. Every dealer has a detailer and they can get it done for you. Make 'em do it!

The white color on NISSANS does not have a clear coat. There were other colors that didn't use clearcoat but I don't remember. I think the white is also referred to as a single stage color. If anyone would explain exactly why, I'd appreciate it. Maybe it's because it's just applied and there's no second stage for the clear coat?

You have two basic types of paint.
Single stage and Base coat/clear coat.
Single stage paint is just as the name describes, it's a single stage of color. No clear.
Base coat/clear coat is the color coat followed with a clear coat. The advantage to clear coat is that it has built in UV protection to help prevent the paint from fading.
Different color paints have different hardness to them. Black is the softest, white is the hardest generally speaking. White doesn't tend to fade or pick up visible scratches as easy as other colors so some automakers choose to not put on a clear coat.

Now, for your specific car. I have never worked on a white Xterra, so I can't comment on if it has clear or not. Assuming it doesn't, a good cleaner-wax will do a great job of giving it shine and protecting it. I prefer Meguiar's Cleaner/Wax for this job. You can find it anywhere and it works great. Just go get a can of it and follow the directions. If you don't have clear you will see some paint transfer onto the pad. This is normal. This same thing happens with a clear coated paint, you just don't see it because it's clear, duh!

As was suggested above, having a professional detailer do the work has it's benefits. But doing it yourself will be cheaper and you will probably find that the results are good enough. If you don't like it, you are only out a few dollars and a few hours of time.

Im not certain, but I highly doubt that a vehicle of that age does not have a clear coat. I just sprayed the roof on a brand new polor white frontier, and it was a factory clear. I have never seen a car from about 97 on that didnt have a clear coat from the factory. Reguardless if it is a clearcoar job, or a single stage whire, buffing would make it shine like new.

that is probably the reason that most white cars cost slightly less than other colors

Most Nissan vehicles that are white are single stage including the X.