Waxing your car makes a difference, but it is so small that you would never notice it.
To put it in perspective, an F1 car gets waxed before a race and even the panel gaps are taped to reduce drag. This yields a 0.05 seconds saving per lap. One lap is about 3 miles long, but races are typically around 65 laps so the advantage is about 3.25 seconds. Every little bit makes a difference.
Taping the gaps make a difference but the waxing is just for show. After the first lap all bar the car in first place are covered in muck and bits of rubber.
Aircraft waxing - for example, the WWII P-51 fighter - was performed by the ground crew. Other searches considered, this may have added a very small speed increase.
The aircraft did not have the same exposure to shredded rubber, airborne dust, oil et al ad nauseum.