I'am buying a 99'Plymouth Voyager Expresso.In about a week and a half.I'am selling my Mercury Moutaineer.I had a system in my 94'Dodge Caravan.But,a 99' it built totally different.

i just added an am-fm-dvd -tv tuner all in dash with a 7.2 lcd screen to my 97 voyager had no difficulties

I'm pretty sure that the 1994 & 1999 radio mount the same way. Your 1994 setup should fit just fine.

I saw on this post that nomoparknowledge installed a lcd monitor in dash! Very cool.
I have a 97 Grand voyager too and would love to do it.
What steps did you take?