Annoying fastener on hybrid battery filter

Honda had that style of fastener, first plastic fasteners I recall seeing, holding the plastic liners in the wheel wells one we had. I think the trick is to press very little when unscrewing, otherwise it jumps the threads, doesn't back out. A flat blade screw driver under the edge of the head, lifting a little, as you rotate the screw counterclockwise with the Phillips screw driver would help I think.

Looks like yours is a little mooshed now, maybe score a replacement.

 

As @Mendel Leisk kindly mentions, clips of this style are meant to unscrew, but not completely. In the Repair Manual (more info), Toyota writes, “Remove the clips by unscrewing the center pin and prying out the shell,” with this illustration:

​

If that doesn’t work, just pull out the existing clip and buy a new one, part number 90467-06165-C0, list price $1.81, shown in Figure 58-04, Mat & Carpet, part name code 58441N.

 

In the OM in section 6.3 “Do It Yourself Maintenance” on pages 546 and following there are instructions for doing this and warnings about what to do and not to do such as

“When cleaning the air intake vent
When cleaning the air intake vent, make sure to only use a vacuum to suck out dust and clogs. If a compressed air blow gun, etc. is used to blow out dust and clogs, the dust or clogs may be pushed into the air intake vent, which may affect the performance of the hybrid battery (traction battery) and cause a malfunc- tion.”

Just some information for those who might be doing this in the future. FWIW