You dont want to put the tweeters in the sub box. 1. The box will be in your trunk, not gonna get much results from a tweeter in the trunk. 2. If you cut holes to mount the tweets in the box, you are breaking your seal on your box and the air pushed from the woofer will flow through the tweets. For placement, you could mount them in your rear deck (next to the 6x9's). Then you wont have to fabricate anything, just drill two holes through the deck lid and mount.