For my old tC, a lot of people were using 9005 silverstar ultras in the 9006 harness. They just filed down the tabs that got in the way of plugging it in. Now I have a pair of silverstar ultras left in 9006. I was wondering if it would be a bad idea to file the tab and put it in my 07 2.5i. I believe the size of the 2.5i is 9005? I was just wondering by doing so would I run risk of melting or messing up my headlight harness?

if the wattage is the same as the other bulb you should not havee a problem. becasue AMPs are what causes the wires to melt.