The only real issue I've had is that I have a UK version of the muffler section. The tips need to be extended another inch or so on U.S. cars because our Federally mandated crash standards require more bumper. EU/UK Fiestas have shorter bumpers and hence have shorter tips than U.S. spec cars. Eventually I will take the car to a muffler shop I trust and have them extend the tips for me. The longer tips are available on shipments to the U.S. thanks to my input (I was the first Fiesta ST in North America to fit test and give feedback to Scorpion).