I waxed my IS about 2 months ago, right before I drove from Columbus, Ohio, to LA. Since then I (regrettfuly) haven't been able to wash/clean my car. I finally went out and got mcguire's gold class shampoo/conditioner and wax. My question is, should i use a dishwashing detergent to wash the car first in order to strip my last coat of wax off, then rewash with shampoo/conditioner, and then apply a new coat of wax? The mcguire's shampoo/conditioner doesn't strip wax. thanks in advance for the help.