Coil seems to be doing fine, at least I haven't gotten any random misfires on startup like I was with the old coil. More importantly, my CEL did finally come back on today with a code P0421 (pre-cat not functioning) and no P0300 (random misfire) so I can get my cat(s) replaced at the dealer free of charge. Unless of course someone wants to buy me a Racing Beat header and Flyin' Miata midpipe, but well, that ain't happenin.