I've recently bought a 2007 S Class (W221 I think). I was disappointed to find that I do not seem to be able to display the speed limit for where I am on the Navigation system. Does anyone know if that is possible? If not, I have a Mio M616LM Sat Nav that I used to use on my previous (non-athermic) car that both displayed the speed limit and alerted when I exceeded it by 3 or 7 mph. I tried that in the S Class but have considerable difficulty getting a good enough GPS signal - due to the athermic windscreen). The satnav does not have an external antenna socket. The only effective solution if I cannot get the speed limit and alerts on the built in satnav appears to be a re-radiating antenna - which I understand is illegal(?) and may impact on the cars electronics. Can anyone advise please??