[TOY4WD]

Is there an after market option?

Yes, parking sensors are available aftermarket. Some dealers even sell them as add-on accessories for certain vehicles but you should be able to find them on ebay (~$15 and up). It usually consists of the sensors, wiring and a module that sits on your dash showing direction of the objects. The tech hasn't changed much from when they had them on the 2002 Lexus LS430 (might have been earlier instances also).

Regarding the IPA - I've used it on the Prius a handful of times. One time it worked flawlessly. The other couple times it didn't like the distances and wouldn't initialize. And another time traffic was congested and I didn't have time to fiddle with getting it situated so just did it manually

 

[TOY4WD]

Can a dealer install it just like factory?

I doubt it but you can ask your local dealers. The factory sensors alone are like $99+ each. If you have to have the parking sensors I would look for a Limited with the Advanced Technology package or investigate an aftermarket solution. If you find a cool aftermarket solution let us know.