First and only one I've seen used. I paid 400.00. Probably half what the tune and labor costs. Yes you can control it on the fly with the app or the switch which I got as well. I tried the 50/50 split once, and it was super noticeable, but probably not good in the long term. I'm coming up on my Haldex service and once that's done I'll really start diving in.How much do they go for on the used market? does it have the app to control it on the fly?