For your pass plus, get in touch with your driving instructor.
As for the mods on the Jeep, click here
to see what mods were done. The reason the insurance came down was that the new engine might be 400cc bigger and pack more than twice the torque, but it also happens to have 5 less bhp than the old engine, and that's the figure CIS looks at.
CIS only gives a **** if you modify the engine, lower the suspension, or fit bigger wheels (not tyres), so it works perfectly for me