Not sure if this is really the right place to post this, but it certainly caused me a techie problem on Saturday

To cut a short story even shorter, I had cause to remove the wheels to check the brake pads on Saturday. Even with the extending wheel nut wrench I had in the Bongo though, a few of the wheel nuts defeated me, necessitating a quick trip to the friendly local garage for a proper wrench (I was visiting my mother, so my main tools weren't available). Anyway, the problem is that the nut's on my Mazda alloys were well rusted on & I didn't have a hope of shifting them without a proper socket/extension bar combination. I'll partially rectify this at the weekend with copper grease, & will add a regular nut removal session onto my maintenance schedule, but I was thinking that a better solution would be some wheel nut covers, to keep the grease in & the crap out - I can find them for 17mm & 19mm nuts, or above 38mm (lorries) but I'm damned if I can find any for the Bongos 21mm nuts

Has anyone else found a source of these? Or another solution?
Rhod