probably a estatre, then loose the back seats and boot for the install (multiple diamond tdx subs, dls ultimate amps, extra batterys) custom made front door panels to mount a 4 way fully active system
then take it to a bodyshop to have the rear doors welded and sealed so it loosk liek a 3 dr
then get brabus to tune it (then get ti to well lane in batley, bolt it to the rolling road and tune it even more)
oh and autoglass on hadn to replace the windows the install will blow out