[lunarhighway]

they don't seem to be to aggressive... so thay're likely to be well within the tire wake.
maybe you could swap the front ones lef-rigth so they mount backwards...that seems smoother... or add some small kamback farings around it (as would be the case if they where backwards), so you get a virtual boattail...

mudflaps have a good side in keeping the car clean and undamaged from rocks so if you want that aspect you might just try to optimise them....if not, loose them

also when you don't strictly need them you could take them of and do some A-B testing