Drive-by Truckers - Angels And Fuselage chords

The last song on Southern Rock Opera is quite simple to play. The verses are a standard 
chord progression, the chorus a four chord, but with a twist.

The song is in 3/4 time

The verses go D, A, Em, Em
The chorus goes D, A, C, Em
[ Tab from: http://www.guitaretab.com/d/drive-by-truckers/344368.html ]
The twist is that your ring finger should never come off of the 3rd fret of the 2nd 
(the D) throughout the song. As such, the chord fingerings are like this:

D  x-x-0-2-3-2-|
A  x-0-2-2-3-0-|
C  x-3-2-0-3-0-|
Em 0-2-2-0-3-0-|

One tip on the verses is that the first Em is hit on the low strings, with the 2nd on 
high string, but with the same fingering. Listen to the recording to hear what I mean.