The mids roll-off naturally, so no need to chop off the high end. Besides, you may make it worse than it is now. If you were to do it right, you would get 2-way passive crossovers and install them in the doors. That way, there would not be any frequency over- or underlap between the tweeters and mids.
Mobridge DA2 > JBL MS-8 > JL Audio HD600/4 > (3) Hybrid Audio L3SE & (2) Rainbow Cal25; JL Audio HD900/5 > (2) Morel HCW-10 & (1) AE SBP15