I thought this thread was gonna die before the second page but hey, as a bandwagoner, I can't help myself...
To answer OP's initial question... Obviously, no-one knows but, at the rate you are going, you might be able to answer that question for everybody... simply disregard the fact that the police are just looking for these type of cars so that they can justify their very existence within "the force" on a daily basis. Continue to drive your car as it sits then come back and tell us all what happens "if you get red stickered more than three times"..
I reckon the only reason no-one knows the answer is because, by the time they get their SECOND sticker... they have learnt their lesson and rectify the car so it complies with road rules.
Good luck out there!