Whilst driving into work this morning my speedo stopped working, needle dropped to 0 for about half a mile, then popped up and worked fine the rest of the way. Read the fault codes when I got here, brings up 16885, which is a vehicle speed sensor fault, my question is where is the speed sensor on my 98 S4? Cheap part, worth changing now? Or expensive, so just clean the connections etc. and keep an eye on it.