You don't need to remove the dash to change a head unit. If you're using the standard cables and connections everything is accessible through the DIN slot once the head unit is out, but it's also very helpful to remove the switch panel beneath as there little room for cables and it's a very snug fit. If you're running RCAs to an amp/s or your own speaker cable there is still enough room for everything. I recently removed an old Pioneer head unit that had a couple of add-on boxes for Bluetooth, iPod etc - there is enough room for all of this, but again, it's very tight for room behind the dash.