The access panel that drops down to access the oil filter was not installed properly and was knocked off on the road. I need to replace it but so far I can find only the entire splash guard. Any suggestions as to where I can find just the access panel, roughly 1 foot square?
Wow, that sucks -- sorry to hear that because you are not going to like the answer. Check out this thread: Can I replace the oil change access door | PriusChat
You buy one of the cheap knock off undercovers off of ebay and then remove the access panel and add it to yours (which is all together better with fit and insulation). I used a piano hinge but you could cut it out larger on the plastic hinge side and add a couple of the plastic pop rivets. Part 5141012105 about $60.
I replaced the problematic plastic rivets with M6 rivet nuts and bolts. On the front M6 screws with the small Keps washers that dig in and cut into the soft thin polyethylene shield, I found and use these neoprene backed conical crush fender washers that reinforce and eliminate the long term cutting and tearing of the plastic. The 1/4 inch hole is a good fit for the OEM M6 bolts.
Or you could just leave it off. Mine has the entire shield missing....no problems in 4 years...and no loss of gas mileage. Just easier oil changes.
Amayama has genuine underpanel (part no ). For me, price shows as roughly $169 CDN, including shipping, from UAE. In past that's ALL I've had to pay, not extras for tax, duty or whatever. Buy Genuine Toyota 51410-12103 (5141012103) Cover, Engine Under, No.1. Prices, fast shipping, photos - Amayama The panel will last pretty much forever, IF you don't use that "flap", just remove the whole panel. That's all I ever do, and it's not that onerous, take an extra 5~10 minutes either way. Remove the fasteners carefully, and ALWAYS wash them out with hot/soapy water before reinstall. This assumes DIY only, If you're employing "professional" mechanics, they'll break it. Part no's for panel and fastener in attached:
Bought my 2010 used in 2019 with 115K miles and it had no under undercover at all. Don’t miss it, mild weather here, low average speeds, makes working under the car very easy.
I'll have aluminum underbody replacements in my car soon, will post pictures once they are installed.
