http://taxdisc-direct.co.uk/
I went through the first stages of entering my reg and car manufacturer, found it odd on the next page where you get to choose 6 or 12 months but it doesn't tell you the amounts, but became highly suspicious on the next page where it asked for all my personal details!

I then went and found the official site...
https://www.taxdisc.direct.gov.uk/EvlPo ... =directgov
As you can see, they're very similar and I had simply thought that the official site had just been revamped.
Just thought I'd bring it to everyone's attention if they hadn't already seen it. It came up at the top of my Google search.