Happy new year and all that.

As the title says,where do i find it? I'm starting the new year as it's probably going to continue,under the bonnet of an A4,as it seems that i will be looking after the car myself as much as possible rather than let the 'specialists' ruin it even further and fleece me dry for the pleasure.Am trying to familiarise myself with the layout of things before i tackle my first two jobs later,being the EGR valve and the thermostat.

On the day (Xmas eve) that we were due to collect the car back from it's two month stay of execution at Exeter,a rush job was perfomed,alledgedly,to change this sensor,which i was told is in the rad.I've looked all around it this morning,above and below and cannot see anything that looks like a sensor...