that is exactly the reason...so the heat doesn't build up and water doesn't get in...btw, i do put them on all the time at night though. i put the stock ones back in until i do drill a hole (did this on my mustang with no problem)i am just lazy... unfortunately i don't remember the size of the bit, but has to be small enough so no moisture can get in..hope this helps.
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"SLEEPER BEAUTY"
