For my Patriot, with the skid plates, there was a hole left open in the plate so you could access the oil filter and another for the drain plug.
The spot for the plug worked great (no messes). I would always make a mess at the filter though. I ended up putting 3-4 paper towels wadded up between the top of the skid plate and the bottom of the motor to catch the spills before they landed on top of the skid plate.