Nah, I don't think people are having problems, its just that no one has tabs or feels like tabbing it out.
I don't really remember how "American Baby" goes. I just remember it wasn't my favorite DMB.
The "Crash" intro is not that hard to adapt to ukulele, but you kind of need low strings to get the full effect of the intro. So assuming you have low G here is the intro:
Code:
A-----7(*)-----7---7---7---7---7---7---7----|
E-----7(*)-----7---7---7---7---7---7---7----|
C--------------------4^--------------4------|
G---6--------2---4-------1---2---4----------|
*after picking the "bass" note you do the strumming pattern on those two strings. The easiest way is to flick the strings with your index finger. You need to listen to the recording to get the rhythm.
^Also you have to substitute the E on the 3rd string (C string) because the ukulele doesn't have a low E to play.
I finger it with my pinky barring bottom two strings (A and E) @ the 7th fret and use my other fingers to hold the other notes. Some of the stretches are harder than others, but they're all doable. I promise.
There ya go.