A appreciate that this maybe slightly OT, but it is DIY and I am sure others here will be able to help.
I have a GPS reciever that also recieved RDS broadcasts (i.e on a standard FM frequency)
The current GPS unit uses a single wire with a phono type plug as an antenna.
As an alternative there is a "Y Adapter" avaliable that plugs inbetween the radio and aerial which gives the GPS unit the use of the main car antenna (improving reception). See links below. The official splitter costs around
35 Euro, but I am sure that there is not much to it and a DIY solution would work.Plugs and bits are avaliable from maplin, but can any recommend the best way to go about this?