Save the $2500 that you would put toward a built-in Nav for a good suspension lift or new tires/wheels. Unless you must for some psychological reason have the nav be built-in. I got a TomTom XXL for $130 (including free current map) and it is good enough for me. Probably not as good as a Garmin, but out of principle I will not spend $300 for the unit and then another $100 just for a city map (w/o topo, which is an additional $100). The non-upgraded speakers sound really good, IMO, as long as party mode is on. I haven't been able to compare them with the JBL's, but the non-JBL's leave nothing to be desired. Plentiful bass. And it blasts out & through the rear door in case you like to show off.
Add that to the likes: great sound system, even without the $2500 upgrade. Oh yeah, and being able to sleep in the back is +++!
I have said this before, but I can't understand why anybody would get a 4Runner if they are just going to be driving in town, except that they look smooth. There are much better city-only vehicles (maybe a Tahoe even

). But off-roading is where this ride shines. Which is why I don't understand why anybody would get anything other than a TE (they look better, too), unless you have a woman that needs the lux or you do like Harper ($$$). No offense to the existing SR5's or Limited's out there. Rear locker is priceless and peace of mind on a difficult trail.