I also have the Sport Graphite in Aquatic Blue Mica, such a lovely colour and have kept my satnav maps updated year on year at a disgustingly expensive subscription of around £50 a YEAR for maps PLUS £55 a YEAR for Live services (which gives traffic and speed cameras)
The tom-tom link posted above is for a full Europe map, you can save money by selecting UK only or as I do, the Western Europe Map. Also, if you add a map to your basket and then hit the back button in the browser, it sometimes pops up a window offering 5% discount. They offer a single download of a UK map for £35 or with a years updates for an extra fiver.
As to the missing SD card, you should get a 8GB card (4GB is too small for updating subsequent maps), format it on your PC using FAT32 format.
Pop it in your car device and then turn the ignition key to 1st position. You should see an egg timer as the satnav initialises the card with your device’s ID info.
Turn the ignition off and remove the card.
On your PC you will need to install Tomtom HOME2 software and create an account (which you use when you buy a map).
Run tomtom home2 and log in to your tomtom account, insert the newly initialised SD card and you then need to associate the card / device with your account.
Once associated you should then be able to select “update my device” and download the newly purchased map.
You should have a USB socket in your glovebox where you can add a USB stick containing MP3s if you like this sort of thing. If you are interested let me know and I will update the thread with instructions for naming conventions etc for MP3s using this. Alternatively you can attach your mobile using the AUX socket to play music.
I have uploaded a copy of the manual for the device and you can download it here: