haha yeah i suppose but if i drive quick enough then hopefully nobody will ever be behind me!! 
Or you could just use that red rag instead of waving it at the bulls
There are 2 basic principles:
Rules is rules - it'd just be advice if you were allowed to choose which ones to obey, An MoT only check you are obeying rules that apply to your car, and not all of them.
The law isn't applied retrospectively - if you did something legally it can't be made illegal after the event by a change of law. It even says so in the Human Rights Act. If you didn't need a fog light (or indicators, seat belts....) when they made your car, you don't, legally, need them now. Doesn't mean they're not a worth fitting though.