are you trying to change them for availability in Europe or for another reason ?

availability in Europe, maybe not in car parts stores, but YOU SHOULD BE ABLE TO FIND THEM at electronic shops ( kinda radioshack, or electronic parts shops where you buy integrated circuits, transistors etc... ). LOT OF Electrical devices use the same car units... big glass ones. I know mostly european electrical devices uses small ones, but still lot more use the big glass ones