2015 tacoma / weather tech floor mats

so i ordered some weather tech floor mats for my Pro,, they are not here yet, i was cleaning the drivers side front out and noticed a lump,, under the carpet there is a retangular 1/2 or 3/4 in piece of foam, what is it, and will it interfere with the way my weather tech mats sit on the floor,, thanks

 

Weather techs are designed to fit around any OEM surface for your vehicle.

 

Weathertechs are on my radar now, I bought Husky floor liners and had to send them back because the fit was terrible along the transmission tunnel.

 

anyone know what that piece of foam or what ever it is , is for, its like 4 in. by 8 in. 1/2 to 3/4 thick

 

got the weather techs today. passenger side is perfect fit. drivers side has 2, 1/2 gaps on the left side of the drivers side mat. like its not made quite right,

 

There are foam pads underneath the carpet in different spots to help with evening it out. Not sure if it really helps though. I noticed these when I removed my carpet/

Many posts about weather tech fit. Lay them in the sun or hit them with a blow dryer/heat gun and massage them into place. It has worked for some people. I just by the WT mats, I like them better for my tacoma. My messy wife gets the liners in the T4R.