If you need to mount at least one wheel once, you need a guide pin first. It's worth it. Especially on my big 315mm wide 20" wheels for my X5 the guide pin makes a world of difference. I use them on my 2004 BMW E46 M3 and they work well. Fresh out of the box the first one was bent on first use. It looks like a manufacturing defect as I installed the other three wheels with a different pin in this set of two and had no problems.I sent the photo to Thexton and they sent me a replacement straight away.Fantastic customer service!