Under the bumper part

[Thomby]

It's the clips. Just make sure that they are snapped solidly into place. It's really easy to mistake them being all the way in when the center hasn't actually penetrated fully into the outer piece. To assure full connection, remove the center piece, push the outer piece all the way in, then push the center piece until it is flush. You'll also feel/hear it click.

There's also that one plastic "bolt" around the center that snaps in place...I believe the intent is to support the panel while you put in the other fasteners.

I bet having the front edge of the panel below the bumper edge, rather than above it, is the source of a lot of these problems as it leaves a front-facing edge for wind, water, debris, etc to snag on. And only putting the rivets through one layer instead of both.

There are also holes near each plastic rivet (blue circle below) that will let you reach in, hold the panel edge against the bumper edge, and feel that the river is through both panels:

 

[Snicklefritz]

There are also holes ...

I never noticed those before. wonder why there are only holes alongside the front clips?

 

[Volfy]

There are also holes near each plastic rivet (blue circle below) that will let you reach in, hold the panel edge against the bumper edge, and feel that the river is through both panels:

View attachment 87180

I freely admit I didn't realized that's what those holes were for, until I've R&R those panels some 3-4 times. Then it dawned on me.

 

[Lee0nidis]

I am resurrecting this post. Anybody remove this and leave it off?

Has anyone found good place to buy the under panel?
Thanks.

 

[Snicklefritz]

I am resurrecting this post. Anybody remove this and leave it off?

Has anyone found good place to buy the under panel?
Thanks.

You know better than to ask that first question. Get it at the dealer's parts department.

 

[Lee0nidis]

You know better than to ask that first question. Get it at the dealer's parts department.

Someone mentioned it earlier. Didn’t know if they were successful on finding an aftermarket.
I also asked if people have removed it and had no issues.

 

[Ah GetFd]

I have posted this before.

This is not an undercarriage protector it is a cover designed to improve the air flow beneath the car

From the glossy brochure...............

""Aerodynamics""

"While the aerodynamic aspects of the silhouette are plain to see, the Stinger also boasts vital drag reduction features that improve airflow underneath the car. It uses specially designed under covers, below the engine and transmission, each side of the cabin and each side of the rear suspension. These covers reduce the air flow resistance on the underside of the body when travelling at higher speeds"

https://parts.kia.com.au/showAssembly.aspx?ukey_product=121577190&ukey_assembly=10850846