Check after body repair.

Our previous Civic Hybrid was in a bodyshop for a month at one point in it's life. When I picked it up the mpg display was at 29 liters per hundred kilometers (translates to 8 mpg US).

And you had to slam the doors to close them!

 

There was nothing wrong with the car, mpg bounced back with the next tank. It was just the horrific "driving" conditions, basically a lot of sitting around idling, 100 foot "journeys", that sort of thing.

I'm sorry, I'm pretty much off your topic, much more specific to the Prime, will get outa here.

 

Unfortunately Toyota (like most manufacturers) do not operate or affiliate with any body shop centers. This is part of the broken US dealer system where Toyota doesn't even operate dealers. The only ones that are manufacturer to consumer, is Tesla. Every single other make licenses a franchise store to Joe Schmoe who is free to run it however they want as long as they follow some very loose guidelines, display banners and logos prominently enough and importantly pay the make franchise money every month to remain part of the "network". Joe Schmoe then has his buddy Bubba who owns Bubba's Body Shop that has even less to do with Toyota than Joe does, meaning nothing at all. But Joe will send all the people that comes to the dealership to Bubba as that's one of their "certified repair centres" or some crap phrase like that which really means nothing at all.

A dealership should only be used for recall and warranty work unless you know and trust some of the mechanics in the back. Otherwise, avoid like the plague. I have had many acquaintances over the years that worked at dealerships from auto detailers to actual wrenchers that "fix" the cars. No way I'd ever let them touch my car.

As to leaving your car there a while, I have you both beat. My then 5 month old Nissan Leaf had been involved in 2 parking lot hit and runs while I was inside stores so it was getting fixed. Unfortunately the vehicle is aluminum so whole new door skins and panels were ordered and welded into place. Took about 3 months for the parts to come from Japan as the TN plant was still tooling up. And another few weeks after that for the work to get done. So brand new car spent half its life in the shop. It's like a Land Rover!