As someone who has been involved with aerodynamics all his life, I cannot envision any application of tabs on an existing MH that would be able to make any measurable difference in the aerodynamic qualities of a MH. When I say measurable, I also include highly technical laboratory measurements that could take place in a very controlled environment.
If you want to clean up the airflow around a MH, start by rounding off all the corners, and if you included a trailer tail, you might see a very, very small improvement.
2001 Coachmen Mirada (Ford F53 6.8L V10) - Toad 2001 Civic
It won't do MACH 2, but I can get a sandwich and take a pee.