Ben, on a 1994 civic there is room behind the bumper for both a secondary 3 inch x 18 inch tank and my 4 X 8 inch horizontal 21 plate reactor which sits between the horn and the trans cooler and is way overkill but works well with the Apexi Neo and an OBD II conversion. The tank does block direct flow of air across the transmission cooler but there is still ample air flow to keep everything cool in Arizona anyway. I have no idea about the newer models though as far a space. I will be looking at two Civics from Nevada on Sunday and let you know if there is space in those models not sure of the years yet.