If you're on C5 coming from the south expressway, you will reach an intersection then pass over a bridge (the bridge is just after the intersection). At the end of the bridge, turn right to J. Borris street (the first street after the bridge). One of the buildings on the right (along J. Borris) is Michel Motors.
Note that I haven't been to this area for 9 years. This information may not be accurate anymore. Hope you find it. If the shop still exists and you place an order, please tell us about it here in Tsikot forums.