Did you get--dare we hope-- a Mazdaspeed 3?
As for stick magnets, I imagine the main problem will be having to build the earcup from aluminum to hold the suckers in place. A plastic cup would have to be designed with preload to counter the flex.
Unless Steve Tice knows of some superdense wood...
Anyway, not a problem for the HP-1.
Assuming your HP-1 sounds a little dull and midrangey stock, the stage one mod is to press a disc of thin felt firmly up against the back of the driver by inserting a thick disc of stiff opencell foam. Stage one point five would be to back the felt up with a disc of aluminum foil. Usually that's enough. You should hear the bass tighten up and actually increase, and the highs will be boosted slightly as well. To get the top octave to come all the way up generally requires an extra step, and many people don't feel the need, so try the simplest stuff first.
Amboina Burl is pretty darn dense, pretty darn spendy too, but oh so lovely.