Piece that may have fallen of our Lexus?
 

Can anyone please help me identify this broken piece of a metal "cap" or "plug" that I found in our driveway? I've attached 3 photos below to show what it is.

It may have dropped off our LS430 or RX350 in the area where we found it on our driveway. We're concerned that it may be a safety issue to drive either Lexus - even to the Lexus dealer's repair shop 15 miles away - until we know what this small broke-off portion of a part is.

Thanks in advance for any help you can provide!!

[IMG]https://i.imgur.com/mmibNA4l.jpg "border=0"
Attachment 648Click For Full-Size Image.

[IMG]https://i.imgur.com/ltKZ39Yl.jpg "border=0"
Attachment 648Click For Full-Size Image.

[IMG]https://i.imgur.com/kF08tnAl.jpg "border=0"
Attachment 648Click For Full-Size Image.