Hi,
So you have a DTD postcard.
Your card should have the search string "GGH722072" which you no doubt used to find this page and is not needed from now.
Your card should also a 5 digit hex number e.g. 1A27C. which you should enter if prompted. If you choose to proceed I do not guarentee that:
a) It will be fun
b) It will be worthwhile
c) There is something at the end

On the off chance that you do here is the first clue.

"In a pile of scrap sits a five star wheel. I know this because it sits close to me on the drive. Hit the centre to start your trail."