I love my Porter Cable and I have shoulder issues.
I use Prima Car Care products and when speaking to the owners they explained that different waxes are better for different types of paint. They do sell a carnuba wax (Banana Gloss) and several Polymer waxes. They told me that if the paint is non metallic that the Carnuba will really bring out the deep shine, but it only lasts about a month. While for mettalic paint it's better to use the Polymer wax. I will apply their Epic Polymer twice a year and then in between I use the Hydro wax which is applied really fast and is a Polymer.
When I do apply the Epic I will first use clay bar to clean the paint, then polish with the buffer to remove fine scratches, then a glaze to fill in any scratches left and finally Epic. This whole process will take about 3 hours so I only do it in the Spring and also in the Fall.
In between I wash and then apply the Hydro seal.
The in between washes are pretty quick, 30 minutes or so.
Odds and Ends Detailing sells Adam's products which are also very good and he's local. Darryl will happily help you decide on the best product for you MINI.
I know this sounds odd, but I really do love detailing my Tigger. I feel like I'm getting to know him better and I also get that chance to look over his exterior and find any issues that I might miss.