I am looking to install a hitch on our 2003 Grand Caravan Sport with a 3.8L engine. From what I'm seeing online, it appears that this is a reasonable DIY task. Some hitches require holes to be drilled, while others do not. What is the general consensus here from those with experience with trailer hitches?

Also, from a link (http://www.dodge.com/towing/D/home.html) posted in another thread in this forum, it appears that the maxium rated weight is either 3800 lbs or 1800 lbs, depending on whether the "Trailer Tow Group" was included on the vehicle. Why is there such a big difference? It's the same engine and tranny, although you don't have the tranny cooler and enhanced rear suspension. Are there other things that the "tow group" includes? A stronger frame?

Primarily, the hitch will be used as a bike rack. However, I also plan on moving firewood short distances, and transporting certain items when we move from our current residence to a new location 75 miles down the expressway; these activities would be relatively rare.