I've said many time to never use winter floor mats on top of carpeted ones (ie doubling up floor mats).
Now Transport Canada has come out with a warning to all drivers to check their floor mats:
Quote » Vehicle Floor MatsInterference with Accelerator (Gas) and Brake Pedals
During Transport Canada's investigations of alleged sudden vehicle accelerations and stuck throttles, we frequently discover that the problem relates to some interference between the vehicle floor mats and the pedals. Typically, the interference occurs when non-original equipment floor mats are used without properly being retained to the vehicle floor. The floor mat can then move under the driver's feet and become lodged either between the pedals, on top of the pedals or under the pedals. Another common problem occurs when consumers install multiple floor mats on top of each other, reducing the clearance between the vehicle floor and the pedals.
If you have installed aftermarket floor mats in your vehicle, make certain they cannot move while driving. If you are going to install rubber mats in the winter months, when doing so, be sure that you remove the originally equipped factory floor mats. Use only one set of mats and make certain that the mats do not interfere with the gas or brake pedal before driving the vehicle.
After installing floor mats, make certain they cannotmove and that they do not interfere with the gas orbrake pedals. Use only one set of mats. If the vehicle is equipped with a floor mat retaining pinor clip, make certain that the mat is installed as perthe vehicle manufacturer's instructions.[/quote]http://www.tc.gc.ca/eng/roadsa...1.htm