this is true there is a standard and modified class and a special class.. as whith most comps i know. the special class means that you can trailer your vehicle and it does not have to be taxed or mot,ed.. but then you must have it in the back off your mind all that monney sitting on a trailer behind and no insurance ouchhh.. the standard class is open to any vehicle but i am sure 99% if not all off major comps you will need a roll cage or a internal hoop.. and a winch on the front would help. the modified class vehicles will have front and a rear winch or just a front winch and a locker back or front or both. and then you have vehicles whith the lot.. vehicles in the special class are no different from vehicles in th standard class it just means you dont have to mot them. the regs may change from comp to comp but as i said 99% off comps are as above.. as far as portal axles go time will tell..