Errr I was looking at the RA's and thought there boring, so bought some Grey Primer and Satin Black and gave them a rub down which was awkward, I removed any dust/ dirt with white spirit and put them in front of a heater to get them a bit warmer so the paint would take, and masked them up with newspaper and masking tape (also helps to get get the tyres warm to help the masking tape to stick to the tyres in this weather) and sprayed the wheel, first with primer in short even bursts left to right(after warming can up first) whilst rolling the wheel across the garage (the whole length of it helps, I find) back and forth do not try to cover the whole wheel in one attempt,then heat again and take your time then up and down at about 15" away from can and put it in front of heater several times then repeated until it was all grey I even sprayed through the back of the wheel to cover the awkward bits!! Then I left in front of the heater for a about half hour, then sprayed the Black the same way..
(Yes you can leave for an age and rub down again and again until perfect downgrading the wet and dry each time to perfect your finish but I was not that fussed wiith these and running out of time, and i've still got 2 to do

)
Be careful the can doesn't spit when you first start with any can, as it could ruin your finish I always have something to hand I can spray at intially (with can held upright) like the neighbours car *joking* just to make sure its not going to spit paint all over your prepared item!!!
Just take your time, esp with Satin or top coat as its the one we all see

I'll stop going on now
Good luck Dave