Anybody know what comedy movie features two drunk guys, both named "Jim"?

Does anyone remember the title of an 80s- or 90s-era comedy film about a young girl who is telling her class about "what she did this past summer"? Her recitation is a lurid tale of her being "helped" by two well-meaning but very intoxicated hippie-guys in an old rusty dilapidated station-wagon, and they both tell her that their name is "Jim". The two Jims get into all kinds of trouble --- picking up a dead fat man who is sprawled beside the road, getting thrown in jail because the cops mistakenly suspect them of having murdered the bloated sop (but then immediately escaping because the inept jailers neither guarded the cells nor even locked the cell door), getting their car stuck in the mud, drunkenly mistaking the "William Tell Overture" for a selection from Air Supply (or possibly "Megadeth", I can't recall for sure), and so on. Ring a bell, anyone? I only saw part of this movie, but I would like to rent it so that I could see the rest of it. So if anybody can remember the title, I would be most grateful.