Any info about hatch button rubber cover melting?

Recently purchased a 2007 to replace my 2005 package 164 that got wrecked on January 7th, 2017 (RIP). See it at the link below if you want to buy from Copart. Ran great and was still doing 46-52 mpg depending on season. 'tis merely a flesh wound but was enough for insurance to total it..

Copart USA - Online Live Vehicle Auctions - Bid & Win

The 2007 has 143k miles and had a failing main battery. I gathered some parts over the last two weeks including a complete Gen 2 leather interior ($400) and a 2011 battery ($600) from a 54k mile wreck (thank you Craigslist). I pulled the seats and side trim, and main battery this weekend. Installed the battery modules from the 2011 pack into the 2007 pack and reinstalled it in the car. Installed the leather (pleather?) front and rear seats and trim. During the work, when opening the hatch, I noticed the hatch switch rubber liner/cover/whatever looks as if it's melted. Almost impossible to remove as it's like tar. WTH? anyone else ever have this? Never seen it on any other Prii I've owned or worked on. Any good solutions for removing/scraping/dissolving without damaging paint or switch?

On a side note, checking the modules from the 2007 battery pack shows 24 are 7.8x volts, 3 are 7.5x and 1 is 6.22...............any guesses what caused the warnings?

 

Ok. Found an old thread regarding the melting rubber issue. Not much mentioned about cleaning off the melted rubber and just replacing the it. Guess I'll experiment with some cleaners and see what happens. Did find a kit on ebay for 20 bucks that has a new cover, screws and tool.

 

Quick update: New rubber cover arrive today. Worked on cleaning the old rubber (?) off, but was just a mess of tar. Had just completed a brake job a few days ago and had some AutoZone brand brake cleaner left over. Decided to try spraying some on a paper towel and holy cow !! The rubber goo practically just wiped off. Cleaned it as much as possible, but there's no way to replace the cover without removing the switch. Pulled the inside cover off the hatch using some trim prying tools, disconnected 4 wire plugs ( 2 license plate lamps, one unlock button and backup camera), remove four 10mm hex nuts and then the outer plastic cover just pops off. The plunger and spring on the switch will slide right out with a bit of persuasion and then it's just a matter of cleaning the rest of the goo off the plunger that wasn't accessible from the exterior. The new rubber cover slides over the switch like an otter box over an iPhone and then 2 screws lock it down. Put it all back together and the hatch opens like new again since the goo isn't interfering with the plunger/switch assembly anymore. From start to finish, it was about 20 minutes. (and about a dozen paper towels)

For those who end up doing this also: Do not spend the extra money for the full kit that has the tool for removing the cover screws. I don't feel you can properly replace the rubber cover without removing the plastic trim piece below the half glass. Once the trim piece is removed, any phillips screwdriver will work. The rubber cover wraps around the switch body. If your rubber went all gooey, the goo is probably backed up into the switch plunger and behind it. It needs to be cleaned out. There is almost no slack in the wire to allow you to just pull the switch out to clean behind it. You'll probably end up damaging the wires if you try to go that route.