Sony XAV602BT TomTom website error update corrupt

ElDiablo12 Registered Users Posts: 14
Master Traveler
I've just bought a car with a Sony XAV602BT in, I was pissed off when I found it had a TomTom attached to it but not a lot I can do.
I am trying to update the maps, they are 5 years out of date, I have followed this webpage....
BUT when you click that link to download the maps, you download them, then when you come to unzip it, you get an error message d7788yrc32x3.jpg

Then you can't unzip it, winzip says it's corrupt.
Why??? What's the point of putting links to download corrupt files that won't unzip?