Lexus RX 450h pre collision and adaptive cruise control - Retrofit possible

[aremat]

Hi,
I am about to relocate to Houston Texas. For some reason I do not understand the RX450h comes without the adaptive cruise control and pre-collision system that I have come to love on my Prius.
You can order a car with it installed, but it takes around 4-6 months or delivery time as it must be ordered separately. If you order it with a new car it'll cost you 1500 usd, so why on earth do they remove it for those few dollars?

Anyway, does anybody know if it is possible to have it retrofit to a 2011 or 2010 model or the car?
If yes, what would it cost?

No dealer seems to have an answer to this

Regards
Are

[MikeRX]

I suspect you would be able to get it installed but it would come with a cost. And getting something like that installed at a dealer wouldn't be cheap I don't think.

Then again if the dealer doesn't even know the answer they may not choose to install it.

Does anyone else know if its possible?