will be an interesting challenge.
tell me:
*is the boot completely sealed off from the cabin? it's hard enough getting decently loud subbass inside a convertible, let alone one with a sealed-off boot!
*what are your plans to access the space saver?
of your options, i would go with number 2. i would expect more of a 'cabin gain' effect (acoustic boost) of the subbass with the subs firing this way directly into 'a corner'.
would you consider ditching the space saver in favour of a puncture kit, and utilising the spare wheel well for part of the sub enclosure?

GT . 3.2L V6 . Q2 . Kyalami Black - Red . Eibach . KONI . ATP 19" . TOYO Proxes4 . Mille Miglia exhaust
155 . 2.0L 8V TS . Grigio Grey - Grey . Eibach . Bilstein . Enkei 17" . Bridgestone RE001 . REMUS