I love the Miata, but as a hypermiler vehicle, it is poorly suited. The roofline is simply not at all aerodynamic ... even with the top-up. Plus, the fabric buffeting adds drag. Adding the factory hard-top gets rid of the buffeting, but you still end up with a bubble-shape sticking straight up from the chassis in the air stream.
I have a Honda S2000 ... even more poorly suited than the Miata because of the increased engine size/power and added weight. One thing I have seen on an S2000 is a fastback hardtop. This is not a simple mod ... more like a transformation of the car. Some examples:
http://www.superhonda.com/photopost/...s_s2kchop1.jpg
ImageShack® - Online Photo and Video Hosting
S2000 fastback image by aceone73 on Photobucket
Despite the loss of open-top fun, the cars look
incredible.
The same treatment, though not as dramatic, is available for Miatas:
http://www.clubmiatamonteregie.ca/mc11.jpg
And some discussion:
Miata fastback!: Grassroots Motorsports forum: Grassroots Motorsports Magazine
I will strongly consider a fastback mod for my
next S2000.
