is the floor carpet size different on the 2008 prius from the 2010

I'm not sure about the difference between a 2008 and a 2010 but there is a difference between our 2005 (which we traded) and our new 2010. I re-used the Toyota "All-Weather" mats that were in the 2005 and put them in the 2010. They do fit but it is not an exact fit. I removed the carpeted mat on the driver's side before clipping the all-weather mat down with the two clips. Again, it works but it is not exact. There is, however, no problem with the mat or it being near the accelerator pedal.

I would assume the same to be true for a 2008 but since I didn't have one, I can't know for certain.

 

From what I understand, the 2004-2009 models did not have any changes in size, or dimensions, so this would likely be the case for any Prius during that (Second U.S.) Generation of the Prius.

However, given the issues with floor mats and vehicle safety, I would suggest that you seriously secure the drivers side mat, or buy a new one to be safe.

 

The 2010 floorboard and carpet is surely different than the 04 - 09. The '10 has a completely new and different chassis.

You could go to a dealer with tape measure to be sure.