Looking at my gallery...here are couple of ideas to think about..

Could we have a shield similar to the Karmann design with the following included ( see below)....or a Yellow or White number plate design..with club wording included, both the above would ..in my view..look good placed under the rear O/S light cluster.... or maybe the outline of the Xfire as used on the forum and FP's tee shirt..we would need to ask about using this..and add our club wording below.

UK-Crossfire-Club...or...Club-Xfire-GB or UK within the shield..

Just my thoughts... Ken