This is what the situation looks like:
I am currently looking for an IS250 and came across an 06 250 AWD and it does not have navigation. My question is, is it possible for a dealer of Lexus to install a navigation system in that IS250? If yes how much would it cost to make it happen? And another question I have, is it worth having navigation in it or no? And why?
Thanks

Is it worth it no cause some of the oem screen go bad. Plus it's a disc base Nav so you'll have to spend $150 to update every time you want to update. Better of with a portable one from best buy or your phone. If you really just want the looks just get the after market kit from fly audio call it a day.

I wouldn't buy one of these cars without Nav. Do I use it? Rarely. Is it nice to have? Definitely. IMO the car looks very cheap without it.

What is NOT worth it is to pay all the money it would cost to have the car retrofitted with factory nav--especially when you are talking about a system that is 8 years old. Doesn't make sense at all.

You can get the flyaudio/China unit for about $600

Dealership will not install it. different wiring. But you can buy fly audio or used OEM unit. There are some threads about how to install it. you can do it around 600-800.
if you go to dealership unit itself gonna cost you few thousand.. probably 2000-4000. plus installation price. Not worth it.
I will say go with Flyaudio. I have Nav IS350 and it doesn't have many options. Fly audio has more options.

I rarely ever use the navigation. I wanted one that had it primarily for the backup camera. It does look nice though and is there in case I ever do need it. It's also nice to have in unfamiliar areas.

I bought an aftermarket Flyaudio/Chinese unit for my 06. came up to just under 600 shipped so it wasn't that bad plus it was an easy install. Pretty much plug and play. Took about an hour to install.

The features are worth it. getting an OEM unit is about $1500 just for the unit and then you have to get a custom made wiring harness thats another $600 since they both are not the same; and thats not inculding installation

Well I kinda brought this thread back up from the dead but I ended up buying an 07 IS250 AWD with navigation. Unit worked fine and now the touch screen sometimes works and sometimes doesn't