I never write reviews on Amazon, but was shocked that everyone but the spotlight reviewer panned this film. Though I can imagine skepticism would stem from Johnny Knoxville being in a movie were he had to act (since he is most famous for the Jacka** movie and TV Show) Knoxville turned in a great performance. He seemed at ease with the character and was able to subtly convey his lines. His understated approach to the part serves to contrast the absurd situation his character is in and lends realism to the film that would be lacking if Knoxville had tried to ham it up for more laughs. The scene where he tries to rent the hearse and can barely mask his anger at the hearse's drug addled owner's incompetence had me on the floor rolling with laughter. I wasn't familiar with actor Michael Shannon before this film but he does a great job as the owner of the hearse. His cartoonish over the top hippie was the perfect Ying to Knoxville's character's reserved Yang. (a point which Shannon's character cleverly brings up.)
As if great dialogue, suburb acting, and a yellow hearse with flowers painted on the side weren't enough to make you want to see this film immediately if not sooner; the sound track alone makes the movie worth watching, it uses a lot of Parson's songs but also other great songs from the era.
In the end this film goes beyond being a great comedy to become a great film. Having Gram Parson's father as a character added a lot of weight to the last half hour of the film, with Robert Forester conveying all the resignation, sadness, and guilt felt by his character his downtrodden facial expressions. This is a movie I would recommend to anyone.