I never removed tires to put my splashguards on either. I almost did, and then decided to turn the front wheels to give more clearance. I never had a problem fitting my drill in place on either the front or the back. Just make sure you use the correct size drill bits. You are required to use different sizes, so make sure you follow the instructions to the letter. Mine went on, look good, and work well. It's one addition I made, that I'm super glad I did. It's already saved my rocker panels from getting gravel chipped. I'm also real happy with the front end bug/stone deflector. It was easy to install, looks good, and has saved my front end from getting gravel chipped as well. Very worthwhile investments.