My previous car has a wheel speed sensor which was a set and forget affair. My current 7 the sensor was a pain from build, it failed the first IVA with it not working above 30, even after being permitted time to try and adjust it and retry a few time. Finally after installing the earth mod and a few hours testing in the garage on axle stand using an oscilloscope, I managed to get a speedo working up to the IVA test speed of 70. But above 90 it would wiggle, bounce and die, until the speed is reduced again. So that's how its been until my last track day, where at some stage in a session it died for good, but I continued on. After the session I discovered the sensor has come lose and had been dragged around, damaging the threads making refitting the nuts a pain, and as it turned out damaged the sensor in some way. Once I had refitted the sensor, it would wiggle and bounce around at 30 and wiggle and die above 90. After fitting the new sensor the speedo is well, normal, somehow smoother than all my previous cars with the wheel speed sensor, but this could be just because I have been used to bouncing and wiggling for a while. The speedo is now like the Tin Top. CC have been crafty with this part, you can buy all the bits for about £55 including the mount, or the sensor on its own for £50. The mount on its own is £20, which is a rip off. You may be able to source the sensor for £30, but without the mount your not saving anything. The mount would be simple to manufacture, if you had the facilities, but as a one off its going to cost you more that CC are asking, so your best bet it the £55 with all the bits