I found this video that may help you out.
YouTube
I actually like it over Wilco and RIGd. Here is my reasoning in the following order...
1) Price
2) Adjustability on how far or near you can set the tire
3) I like how the tire is angled
One last point. Anything over $600, you might as well save up for a rear metal bumper. I'm not knocking the other two brands. I think they are great and very robust. I'm just a bargain hunter.