Adding Trim Package Bells and Whistles

Hey all-

Longtime listener, first-time caller. Priuschat threads have been very good to me over the years.

My family just traded in our very well-loved Gen II Package 6 Prius after 217,000 miles. The ol' guy was just suffering from too many ailments to attempt to fix them all—using oil, front suspension wear, rear hatch leaking into spare tire well, digital display intermittently going out, brakes needing repair. We got all we could out of it.

We ended up with a 2012 Prius v III. I would've chosen a higher trim level if I could, but these happen to be immensely popular in my neck of the woods (Portland, OR, and now you know the origin of my username). The v is great for my family of four and I hope it'll last us at least as long as the gen II, but there are some things from the package 6 trim level I miss immensely.

I don't miss the JBL speakers and leather as much as I thought I would, but I do miss the smart key door handle sensors on the passenger door and hatch lid. Is it relatively easy to swap out components and include these sensors (i.e., is the wiring there, and just not used)?

I feel very confident in my ability to take apart the hatch lid and swap out a sensor or even the whole hatch handle cover; not so confident that I could take apart the passenger door and replace the handle.

Thanks in advance for any advice.