Parking curb vs Grill and Underbody (serious damage ... help)

I'd guess the (black plastic) frontmost undercover piece snagged on a concrete wheel stop, then snagged and acted like a lever, twisting the bottom lip of the (painted) front bumper (more realistically a fairing), which in turn popped that grill piece out. That frontmost piece is a poor design, like a barbed hook when it drives over wheel stops, then snags when you back off.

You can remove that frontmost undercover piece without raising the car at all. A 10 mm socket on a ratchet wrench (preferably with an extension, say 3") is all you need to remove the combo of bolts (that screw into weld nuts) and screws (screw into nylon blocks in the front bumper lower edge. You'll need a flat-blade screwdriver too, to pry the one plastic push-in fastener.

 

Item 19 is the frontmost underpanel here:

Bumper & Components - Front for 2010 Toyota Prius | Toyota Parts

More detailed info, in particular for the fasteners, here:

FRONT BUMPER & BUMPER STAY. 2010 Toyota Prius Hatchback HYBRID | Toyota

Amayama link (a site I've used):

Buy front bumper & bumper stay for Toyota Prius XW30 (01.2009 - 11.2011) - Amayama

Amazon links to what I think is an aftermarket equivalent for the frontmost underpiece, a lot cheaper. Currently out-of-stock on Amazon.com, surprising in-stock on Amazon.ca:

(You may need to turn off ad-block for the Amazon links to display.)

 

Those concrete wheel stops are pinned down with 2 rebar spikes. You have to be extremely cautious about snagging the underpinnings of your car on those spikes if they have worked their selves up, out of place. Keep an eye on any parking spaces that might be affected.They act like a tow hook that can rip the bumper clean off. This was the case with my Son’s 2012 Hyundai Accent.
You might want to contact your insurance to see if there may be any type of coverage.
IMHO, this should be the responsibility of the party that owns the property.

 

Our son encountered one of those, rebar sticking up about 4". This was with a Civic, ripped a nice chunk out, the bottom edge of the front fairing.

Still, with the 3rd gen Prius, the concrete alone is enough to snag. It's like a fishhook, grabs when you back off it, and if bad enough, tears the rear of that first underpanel piece off the bolt head, then it's free to lever the bottom portion of the front fairing.

 

Yep.

 

Yeah as you can see in that pic, the top edges of the four deep bolt wells take a lot of abrasion, from concrete curbs or wheel stops. And with the latter the whole thing can ride up-and-over, then snag pulling back off. Piss poor design from Toyo.

The work around is to monitor it, repair occasionally. I've used 2-part epoxy coupled with fiberglass mesh. Bought nice big bottles of the stuff, and of course one of them has solidified on me...

Oh, and get into the habit of not driving right up to the end of parking spots.

Maybe either will do?? The bold one is what I got once, when I lost one. Forget how I figured out what I needed, but that's the part number in my invoice.

I take the engine under panel off completely for each oil change. And those bolts are at it's leading edge. When reinstalling I put the bolts in loose first, and leave them thus till all the other fasteners are pushed in. Then tighten the bolts. Except I forgot to tigthen them one time, and one rattled right off.

 

I encountered some front end damage this summer when something flew off a passing truck. Took the job on myself so i got a little more familiar with the front end. Those parts you circled on the lower spoiler were no longer attached to the old spoiler on mine. They were however still attached to the underside of he car. Years of rubbing on the curb stops had ground them off. I did not notice the pieces mounted with the bolts till I had trouble getting the new one to line up.
The sensor on the wire is the air temperature sensor for the dash display. The mounting clip on mine was damaged but a zip tie now holds it better than the original method.