I completely clean the undercarriage before the first show. Although I do not use emery cloth on white wall tires, emery cloth works very well to brighten raised white letter tires. Fifty years ago when I graduated HS and before college, I worked in a Goodyear tire factory. The white walls and raised white letter tires were produced by grinding though the black top layer of rubber to the inlaid white layer so don’t worry about using the sand paper as long as you are careful to prevent getting into the black and smearing black onto the white wall. I have constructed a ring of galvanized flashing with the ends taped together which fits snugly between the steel wheel and tire which allows me to paint the wheel if necessary and not spray any paint onto the tire,
Be cautious to use jack stands on a solid concrete surface. Jack stands without a solid base can sink into hot asphalt or dirt. Never get under a car supported by a hydraulic floor jack without jack stands or a mechanical support. Many years ago I had a seal blow out in a floor jack which dropped the car immediately…fortunately no one was under it as I was preparing to place stands under it.
Be sure to use Sta-bil or a similar fuel treatment before storing your car or letting it sit for an extended period of time. Use a battery tender instead of a trickle charger to keep your battery charged. The trickle charger will damage the battery over a period of time.