TBH id be going along the lines that your car is NOT a focus. In registration and legal terms it is not a focus.

It is a custom spaceframed kit car using focus bodywork.

Obviously it would help if it was correctly registered as such to back your cause, but ive no idea how AG/you registered the car in the first place (if at all).

It is no more a ford focus than the SHP "RSR Escort" is a Ford Escort and thats how it should be treated in terms of race regulations.