Hi,
Yep was me, Steve and Bert in the white 318iS bought from JimBob a few weeks ago, and now sporting some H&R roll bars F&R, Oil cooler ... and exploding brake pads !
Closer investigation showed that the disk / caliper /pad combo was fine with plenty of pad left but once the pad got worn to 2mm the outside one could get past the caliper .... YIKES !!

Brown trouser moment coming into Gerrards at a ton !
Fixed at track side with a borrowed second hand pad and started to drive home slowly when the otherr side went BANG too - not funny !...... ended up clamping the pipe and driving to Derby with 3 wheel braking !!
Measured up some disks on other cars there and there was about 3mm diff in thickness... i.e. the ones on ours were 3mm thinner...
Now bought some vented ones.... and some clean underwear !
Note to All - keep with the vented ones !!
Other than that a top day out.... all the E30 racers were really helpful and chatty ... some useful info on different types of disks and pads were offered
Agree about MX5 drivers though , they are obviously deaf as we weren't that much slower than them and yet they still dived down the inside at the bends before we could get to a straight to let them past on !