Wheels look great on the SG!!! Makes a huge difference over the same wheel in stock silver.
I have dipped stuff on my car and cars of friends of mine several times now. I can offer a few tips and hints for people who are new to this.
Cleaning and prep - very important. Clean everything really well before you start. Taping stuff off is less than important, as some people have mentioned before. This stuff comes right off of everything. It is nerve racking the first time you spray it right onto the paint, you wonder if it really will peel off like everyone says it will. It does. Light overspray rubs off with a micro fiber towel/cloth.
Light coats at first. Take your time. No rush. Each coat that I spray after that initial coat gets a little heavier. About 50% transparency for the first coat, and I let it dry completely.
Grey as a primer? I tried it, as recommended for dipping over white. Works just like primer would. The first two coats I use the gunmetal grey (Home Depot now carries this). The coverage is the best of any color dip I have used. Using the gunmetal is a primer, I can cover something white in 4 coats, instead of trying to use just black, and taking almost 7 or 8 coats. It is amazing what the grey does.
Riptide - the wheels that you did look perfect. That is the finish that you want. If you ever decide to do them again, you don't need to take them off the car. Look at DipYourCar on YouTube. They have some really good instructional videos and offer a lot of tips and tricks on how to get a perfect dip.