It's another white plastic thing to me, but I am intrigued by the rather ostentatious bit of plumbing under the fuselage. Reminds me of my early motoring days in the 60's, when your sporting vehicle had to have the largest, and loudest, exhaust system you could find !
A far cry from the streamlined milk floats that the green lobby will have us all driving soon. Those poor kids will never know what they missed......