Hey, Stryker and welcome to the site. I was stationed in Germany for several years, and never drove much over 100 MPH. (180 KPH) But, if you are driving that 05 155 MPH, you shouldn't be hanging any body stuff on it that is likely to blow off and damage another car. The Polzei frown on that. Just wait until you get home with the car to dress it up. I am assuming you have 355 gears out the back. So, changing the gears won't help you get to 155 any faster because 410's won't even allow you to go 155. About the only thing you can do in the Auto Hobby Shop on post is to install a blower. That will basically make the 4.6 a Cobra engine. Good luck with your decision.