Ford Sierra Insider Infos

Hello together, as you can see I’m new here! I came across this forum when I was looking for information about the Ford Sierra. Since I’m thinking about getting a Ford Sierra, I have a few questions for you: -what’s the difference between 2.0GLX and XR4i? Both have 120 hp and rear drive or? -what kind of maintenance costs are there for me? (taxes, liability…) -what’s there to consider when buying? that’s enough for the first time! Thank you for the answers! Moritz