I run two head units for the same reasons these other guys do. I already had a Pioneer unit that supported AUX input (with adapter.) The cheapest way for me to add my empeg was to just pipe it through the existing system. Plus, I do still use the radio occasionally, especially when my empeg is out of commission. The CD player comes in handy occasionally too, but not too often.

Check my gallery to see what I did with my Blazer, which is also 1.5 DIN. You could probably do something similar with a commercial DIN under-dash kit.