Here's a tip for drilling through hardened steel, and I mean the stuff that the best quality drill bits can't make a mark in.
I bought a worm drive wiper for my Avenger and opened it up, I found that the degree of swing was adjustable by inserting the linkage arm into holes that are spaced further and further from the center of the gear, however the degree maxed out at 120, so I decide to drill another one further out to try and get closer to 170 to clean both sides of the windshield. I attempted it with every bit I could get my hands on including a center drill from my lathe, barley made a mark in it. I took it to the machine shop here and he said he couldn't drill it, but a special carbide drill (not the ones made from carbide) but a 2 flute carbide headed one may work.
Well I went to the internet and started reading, somewhere I read that you could use a masonry bit, so off to Canadian Tire and $2.50 later, I tried the masonry bit in the drill press and........ whammo, cut through like a hot knife through butter !!! Amazing !! I am still amazed as this stuff was HARD ! Like I said, the best drills barely made a mark and burned out the bit right away.
So save some money and try your masonry bits when the going gets hard !