US style turn signals
On miata's, the center part of the front combination light is used as a running light. European cars however only use the wimpy corner section of the unit as a running light.
If you want to change to the US style lights, you could of course buy new light, but these are rather expensive and hard to get hold of in Europe. A cheaper solution would be to modify the Euro style units to US style. To do this, all that needs to be done is to open the light and remove the orange lens. Then the socket for the lamp needs to be changed. The US sockets have 3 wires, whereas the Euro units only have 2 wires. The little socket on the corner can either be left in place of be removed, because on US cars this is not used. Cut the old one off and solder the new one on. Connect the third pin to the wire of the little corner socket. You don't have to cut off the little socket if you don't want to. That way, the corner section of the light block will light up also.
To open the light, simply put it in the oven at about 160F for a few minutes to get the glue to melt. Then the front can be gently pulled of. Now you can remove the orange lens out. It's kept in place with just 2 screws. Undo them and remove the lens. Don't forget to put the screws back in! Then you can put both pieces back together. Make sure that there's enough glue to keep everything waterproof. You'll probably need to heat them up again because the glue will have hardened again by now. If necessary apply some silicone on the edges afterwards.
If your oven doesn't go that low, you could also soak the light in hot water. You must be very careful when you do that though. If water gets on the mirrors, these are immediately damaged beyond repair. The turn white in an instant (don't ask me how I found out).