I think it was the Auto-vox T2. It was a pretty basic setup with the power wire run to reverse lamp on the driver’s side. It only turns on when it’s shifted in to reverse. You could probably rig it differently.
Since then, I have purchased a ‘99 LC that already had a upgraded double din head unit with a camera plug in the back. The previous owner hadn’t set it up. I bought a $20 camera off eBay and wired it the same way and it works (although the wire path in the tailgate was different and not quite as simple as in our ‘00 model)
I will say that I prefer the rear view mirror screen placement over the head unit, but still cringe at the thought of all of the modifications I had to do to the adapter for the aftermarket screen/mirror to attach to the windshield.