Any time I try and set the x-flip bit on a 16*16 16 color sprite I get a standard "Dualis has crapped itself report request". I noticed another post with Y flipping. Is this the same error? It sounds like it could be.

Zapf Bandit

Hflip works for 16-color sprites already. But if the sprites goes partially off-screen it will crash since clipping isn't done properly for hflipped 16-color sprites.

Yep, that explains it. I tested with the sprite located near the middle and that works beautifully. It's just that the sprites are constantly moving offscreen. Rather than using the flip I'll just use 2 sprites for each car. It's not like I'm going to run out of video memory making frogger