i didt cut any rubber off any pedal when i did mine all one a treat and no movement but im used to being in my footwell and orquard areas in my car the accelerator pedal just slips over the original hard plastic thing that is there easy done 10 mins max for all 3!
 
im glad im not the only one that can put three pieces of metal/rubber on a car they were specified for without alteration... shorly not that hard if u have paitience....

TT pedal rubbers were not specified for IBIZA's, my IBIZA's gas pedal is deffo different from a TT one, I know cos a guy 3 doors up has an older TT and he let me have a look

modification was deffo needed on mine as the gas pedal cover would not fit at all with out
 
i think its more down to how the rubber is shaped underneith, if you look at it under side of it there not the same shape (to tired to even try and spell the word im thinking of) i did think the same sooty22 abut them just being the other side but no ASudi have to go one step further made make seperate ones!
 
fitted mine last week....piece of cake.
Make sure you u order the left hand side of the accelerator pedal not the right one.