Aftermarket navigation install (2010 Prius IV w/ JBL)

Vehicle: 2010 Prius IV; JBL system with NO navigation.

I'm piecing together my stereo upgrade and believe I've done all the research I need. I'm going to use a Pioneer AppRadio 3 with my Android phone, which should allow all the features that I want (use of Google maps, YouTube, weather updates, traffic). Along with that, I'm aware that I need the PAC TATO module to connect into the JBL system and the Metra kit to wire the aftermarket system into the factory harness. Lastly, I plan to order the ASWC1 to retain factory steering wheel controls.

Two of the things I'm not sure on, yet, and was hoping for some info (recall, this is in a non-nav JBL model):
1) The VSS cable that (from my research) appears to be under the seat--purple cable going to the amp. What does that do? I understand its use in the factory setting, but do I need to hook it up to my aftermarket setup? If so, what does it do?

2) Will the dash controls (trip/odo, HVAC control) that are on the steering wheel still work? I haven't read that it doesn't work and that would be a big issue...but I figured I would ask anyways.

Thanks!

 

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