Thanks for the interesting answers everyone. So, I'll guess my friend's Lincoln, though high end, won't have an internal amp. And his Geo? Hell no it won't. Well, that stinks... he bought the empeg assuming that he had the mythical internal amp to just connect the empeg to.

Hm...... what if... the stock head unit could be ripped apart and shoved somewhere in the dash, using it purely for its amp. Sure, this varies by make and model, but I wonder... Ah, I'll just have to read up and see what Crutchfield tells me.

Thanks again.