Putting vent/drain holes in the tires is critical. My older tires are so full of water and dirt, they are dangerously out of balance. I put 4 holes in each tire with my soldering iron and put the car on its back then hit the throttle. Lines of water sprayed out. One older tire was wobbling so out of balance I had to put 8 holes in it. The wobbling looks like it puts a lot more wear on all parts of the car connected to it.