My dealer included Honda floor mats with the car(!). Unfortunately the retaining post on the driver's side was missing so that mat would slide forward and interfere with the pedals.

The dealer ordered a retaining post but the one they got did not fit (basically too short, wrong shape). Apparently this is complex and they are working on it.

Evidently others are having the same problem, so here is a temporary fix:
(1) get a screw (perhaps from your dealer) that fits into the plastic fitting into the floor that is for the screw that will hold the retaining post
(2) screw it in only part way
(3) get a zip tie (aka cable tie) from a hardware or Radio Shack, loop it through the hole in the carpet and around the screw, and draw it down to the appropriate length - you could also use string or a shoelace

 

my insight came with aftermarket floor mats. i cut small slits in the rear edge of them and used black ty-wraps to secure them to the seat rails. they dont slip forward, and i just flip them up after cleaning them to vacuum under them.