Ive got a right angle adapter on my drill. I can only use small bits,if i go to a bigger bit the drill wont fit in the opening. I hate to have to go buy a new right angle drill.
Use a dremel and a cutting wheel. Some pop rivets have a harden steel mandrel that often gets left in the center of the rivet. I suspect you are running into that and trying to drill that out will be next to impossible. Tackle it from the side with a dremel.
I didnt trust myself to use the sawsall,i probably would have cut my dash in half. I found some type of metal grinding heads in my drill bit box that worked great for grinding the heads off the rivets. Took about 30 minutes. Thanks for all the advice guys.