Here's something to try if you have the DVD navigation system... Or alternatively don't bother and just take my word for it
I was sitting in the car the other day, bored and waiting for someone. So I decided to have a play with the sat-nav. I ended up messing around in the 'Points of interest' section.
Put in Tesco and it brings up lots of Tesco supermarkets. Put in Asda and it does the same. Ditto Sainsburys. I didn't realise it had them in.
Then I went onto car dealers. I've tried to find Renault ones before, but with no success. So... Put in BMW - up pops a list of over 200 dealers. Put in Audi - up pops a list of just over 100 Audi dealers. Put in Vauxhall and you get a handful of Vauxhall dealers, plus a few references to the place of the same name in South London.
But put in Renault and it doesn't even recognise it. If I want to find a BMW dealer to service my Renault, then I'm fine, but if I want to locate the nearest Renault dealer, I'll need to get on the Internet or find a phone book.
I realise they buy in third-party navigation data, but you'd think that they'd arrange for their dealer network to be on the one that they chose. This is on the 2005 disc by the way - they might have improved it on the later ones.