A manual trans is on my long term list. I do prefer them to autos for a variety of reasons. But for now, getting it on the road is the goal. I'll be able to find a cheap yota manual if I have time to find a rusted out truck with all the bits.
Nice ideas on the diagram too. I wish I didn't have the size limitation.... Maybe I'll start making a lot more $ soon and build an addition to the garage.
I've decided it's going to be easiest to do the rounded corners with the 4" ducting opened up. Especially up on the roof front.... I'll need a few lengths for the horizontal and a couple for the verticals. Might be a little ugly, but I think I can dress it up nicely enough. Modifying the frame would be way more work.
My experience with my 65mpg Civic VX has taught me that much of the gains in normal cars are in the rear. The boat tail should help, although it seems less than it did in the VX. (which actually has a kammack)