The aerodynamic modifications are the last part of the project to go on, after all the guts are done. The most critical of these is the body pan, which also serves to protect the controller and motor from water splashed into the engine compartment. It should also provide a substantial improvement over the stock aerodynamics.
Next in line is the front cover. Since there is no large radiator dumping out tens or hundreds of kilowatts of waste heat, the entire front grille can be covered over, save for a small section to direct cooling air through the electronics cooling systems and to provide intake air for the cab. The vehicle's profile may be modified slightly at this point to direct less air under the vehicle, but since it's a truck, with correspondingly high ground clearance, not much can be done about air under the vehicle that the body pan doesn't already take care of.
After that, an aerodynamic bed cover would provide for the greatest gains, but building it will be expensive since it's such a large area to cover. It may not be done at all if the budget is too tight. Wheel fairings will provide for a somewhat smaller benefit with much less expenditure.
The plan at this point is to build all the aerodynamic additions from fiberglass, since they need to be relatively light and strong without becoming too expensive to build.
More to come as it happens . . .