I recall on my old Falcon, when the tyres were changed, the tyre shop added some lead onto the outside of the alloys to ballance the wheel / tyre I presume. Looked exteremely fugly.
Is this method of adding weights still used today for balancing. If so, can they add the weight to the inner side of the alloy, where it is out of sight.
I'm getting my new tyres next week and the last thing I want is a piece of lead stuck onto my Z's alloys

 

'm getting my new tyres next week and the last thing I want is a piece of lead stuck onto my Z's alloys

I'd be surprised if you do not have some weights on your wheels already. I'm not sure if I have ever seen a wheel/car without them. I'm guessing that they are just well places and out of sight.

Is this method of adding weights still used today for balancing. If so, can they add the weight to the inner side of the alloy, where it is out of sight.

Yep, they can and as far as I know that is the standard practice these days. Though, it depends on how much weight you'll need on how obvious it is. Also, sometimes the wheel/tyre needs to be balanced right in between spokes and you either live with the weight there, or you specifically ask them to add more weight behind the spokes to achieve balance. ie. instead of weight X in between the spokes, you could get two bigger weights behind the nearest 2 spokes.

 

Never really looked behind the spokes to see if there are any weights, but makes sense that there should be for proper balancing. That said, I would not put it past Nissan to just mount the tyres without balancing (LOL).

However, rather than having the weights stuck right behind the spokes, can the weight be positioned on the extreme inner edge of the wheel if it has to be between spokes (ie inner edges as appear looking at rear tyres from behind the car).

This way, I would imagine that the weights would just about be impossible to see when looking at the wheel / tyre side on.