I know I shouldn't expect this movie to make sense...

...but I don't understand the plot point about Critter's funds on the road trip to L.A. First he displays a hundred dollar bill at Eat, then, seemingly the next day in the diner, he claims he's only carrying Nepalese currency, THEN he says he can cover his share and $15 in addition. So...where the hell did the $100 go? Why did he bury the lead about having $15 American? Was there a much longer passage of time than the film allows between Michelle and Buzz leaving the diner and meeting up with Critter on the road, enough time for him to have gone to Europe, converted all his currency, and come back? But if that were the case, why would he have been asking where California went when he left Eat, then be on said route to California at the exact same time as Michelle and Buzz? Is the implication that the $100 belonged not to Critter but to the family he was traveling with? That still doesn't clear up the issue of why he claimed he was exclusively carrying Nepalese currency when only a moment later he produced American money.

This is an exceedingly stupid thing for me to be worrying about. Please help.