If your paint is in good condition why are you wanting to polish? If you want to maintain the shine & protect the paint you'd best be looking at a sealant or wax instead. Try Mequiars NXT wax or Chemical Guys Jetseal.

The key isn't just in the polish, it's the technique as well. What you experience with polishes might be different to others depending on the paint quality/colour as well.

Do your car a favour & check out detailing forums online for tips on how to do it properly. www.detailedimage.com is a good one, check the auto detailing guide.