I'm about to purchase an IS in November. Regardless of however good the factory stereo is, I'm pretty sure that I'm going to replace it with an aftermarket one.

My question is, how much harder would it be to swap out the stock headunit with an aftermarket one if I had NAV? How closely are the two tied together? If I had an after market headunit w/aux inputs, I should be able to do this right?

I've thought about an aftermarket NAV, but I just love how the stock one is integrated so nicely with the dash. Or does anyone know if I can install the OEM motorized dash mechanism in place of the dust collector w/ and aftermarket LCD?