DJ, you won't be dealing with Trikes and those type of aircraft because they most probably wont have the approved engine.
An approved engine will most probably consist of a Rotax or Jabiru 4 stroke motor. No modified car motors or 2 stroke engines.
And give these pilots some credit because it would be common sense NOT to put an aircraft like that into a major airport unless it is an emergency.
Besides, I've seen C152's and C172's coming into YPPH, YMML and even YSSY on a number of occasions all under the VH register, so what are your thoughts on those pilots?