I agree with Andrew about 4 times of year is enough when using a quality product. If you are a fanatic and as **** as I am about a clean shiny car, then 6 - 8 times a year is adequate. My Roadster is black so everything shows up on it. I do not recommend using a circular motion when waxing, especially if you have a dark colored car this could cause light swirl marks or scratches in your paint. Start at the top of your car and then work from bumper to bumper. If this is the first time you are waxing your Xfire I would suggest using Dawn dish washing detergent to strip the cheap wax that the dealer put on when prepping your car. Invest in good detailing products, paste waxes are truly better than the liquid products. Its a good idea to use a good paint sealant before waxing such as 3M Imperial Hand Glaze or Mothers Hand Glaze & Sealant. Now you can wax your car to whatever degree you wish.

Here are two very helpful sites:

http://www.autopia-carcare.com/index.html

http://www.meguiars.com/

Hope this helps.