I am in a 4runner... looking at a few options. Thanks to all for the great tips!
@AZcube
I run the Tekonsha Prodigy P2 in my 4runner (and Tacoma and Dad's Ford van and Sequoia). The 4Runner and Sequoia were the easiest to wire up. there was a pig tail in the glove box and we just wired it to the pigtail that came with the P2. The Ford and 97 Tacoma were a bit harder as we had to wire the power and relay since they predated factory tow wiring. I bought the needed stuff all from etrailer.com and worked with Patrick a few times in their technical dept to get everything wired up correctly on these 2 rigs. (I recommend them as their support was excellent both before and after the sale.) I bought a few of the little pockets to hold the controller and have them mounted in each rig. Pull the wire, pop the little box out of the pocket and pass the controller between rigs depending on who is towing the trailer.
From what I recall of my discussions regarding the P2 vs the P3 controllers: Both have the same software and effect the same results. Since we are only towing 1 trailer we don't need the extra buttons and multi-trailer memory features offered by the P3. IIRC my brother went with the P3 (or a similar spec. controller from another maker) as he tows a large number if different trailers for his work and found it nice to be able to store a few in the memory so he was not having to re-tune the controller a few times a week. That said the tuning on the P2 only takes a minute or 2 after hookup and I have not found it to be a big inconvenience.
Today I would probably get the Redarc Tow-Pro Elite Trailer Brake Controller because as
@loper mentioned you can mount it up under the dash and only use up a single button spot on the dash. I'd like not having the little box near my knee. I've bumped the pocket in the Tacoma and while driving the van a few times. The 4Runner is a bit better as I have it mounted to the fuse box cover and can just remove it when not towing. (I'll probably pick up another fuse box cover next time I find a 4th Gen in the Junk yard so I can just swap out the cover with the pocket for the one w/o. If I get really ambitious maybe I'll 3d scan the pocket and cover and 3d print an integrated replacement unit :D )
As others have stated the rules vary from state to state regarding if you need a brake controller. I don't need it here in CO but find it very useful when towing in the mountains.
Boort