[aerohead]

here is an image which suggests what a boat tail would be all about
in the second image we see how the Schlor cars aft-body is improving things
in the 3rd image,VW's 1-liter car has attached flow all the way to its tail end
4th image is SolarWorld GT slipping along at Cd 0.14
5th image is base-drag free 2013 CUER
6th image is Dave Cloud's base-drag free 2004 'Dolphin'
7th image is Paul Jaray's 1922 'pumpkin seed',Cd 0.09
8th image is from Porsche
9th image M.A.N. intercity bus
10th image
11th image 'wake-be-gone!'
12th
13th (wear a respirator)
14th ouch!
15th image:a CFD look at things
16th semi-trailer wake CFD
17th image:simplified wake management
18th: SST's boat tail
19th:more current research with Ahmed et al model
20th:K-form BMW,1938-(aesthetic compromised truncation)
21st:a proper K-form truncation(Cd 0.186 vs 0.23 for Kamm's best)
22ndartial wake visualization of semi
23rd: van wake CFD
24th: '1980 NASA Van' with wheel skirts and more proper boat tail
25th:she's very unhappy about her base pressure
26th: incinerating the wake ( look for the kit at all Pep Boys)
Another CFD
From long ago