All the rust that forms on the inside, regarless of whether you drive it in the rain or not. No, I never bothered to drill the cap. And no, I forgot to do it again this time. No, I don't put a light coating of dielectric grease on the tip of the rotor and on each electrode. No, I didn't even bother cleaning the rust off -- even though the MSD tech support says the rust over the magnetic pickup can shorten its life. Mostly, I just took a snapshot of it so I could post it here and complain.
