possibly a dumb question about nav?!

[vabeachrunner4]

Hey all, ive been reading on this forum for months now and it helped me with my purchase of an '08 X5 Sport, etc. just last week! anyway, the first thing I noticed was the the nav is very outdated and non-user friendly!ive had Acura's and several Pioneer units in the past that are way nicer and easier to use....Ive been searching for days now and havent found the answer to this so maybe it doesnt exist, but is there any way(s) to add an aftermarket nav (preferably) a pioneer unit to the existing computer and be able to have an upgraded nav while still being able to use the other idrive functions? i realize that you may use a few audio features and that may be ok....or what about doing a plug-n-play with the next generation nav coming out next spring?? (only thing there is, ive read that it will be an upgraded resolution display and im not sure if it will be the same size)...any ideas or suggestions would be great!!

also I would ideally like to make it as stock looking as possbile...ive seen the dash kits available and some of them look good but i definetly dont want a free form that doesnt look as stock as possible...thanks again!!