stuff I found

[kyron]

player cast bar sometimes doesn't show in combat, the health layer is above the cast bar.
no focus frame

you should see if you can add text on the cast bar for spell/ability name.

haven't tested vehicle frames, but i thought i would mention them in case you forgot

[teschnei]

i'm just going to move the cast bar into it's own frame - being the hp bar is just causing more problems than it should. this will fix points 1 and 2.

vehicle frames should work, but i havn't tested either (lets go to ulduar and find out)

[kyron]

works great, managed to test out vehicle bars. while testing my entire screen turned red, but i think that was either part of the game or an unrelated addon.

i have one more issue, add a combat indicator of some sort. anything from a dot or changing the color of the player name text.