john-funny you posted this, because i was just about to start a thread similar to your question.........
although i do not know what a "class III trailer hitch" is,
i know the 300C has the towing capacity for a decent sized boat/trailor, its the question of whether or not you want to ruin the looks of the beautifully designed rear end with a gaudy 'trailer hitch'.
im in the midst of purchasing my first speed boat, and im debating whether or not to get the hitch for my 300....? i can tow it with my land rover, but then again i hate taking long car rides in that tank, and not in the comfort of my C.
i wish they made a hitch that was removable, and when not in use unnoticable.