You might consider looking into some of the "Professional" alternative spray nozzles you can get that will fit on to the majority of spray cans.
They are sold in artist shops and the like, although if you want the best selection look online for people selling street art (it's not graffiti they promise
) supplies.
They have a huge range of different nozzles which will alter the spray pattern hugely, from very fine and precise lines to fine mists with almost no splatter.
I've got a few I bought some years ago and they are fantastic, cost a couple of quid each - I wish I knew where they were or I'd send you a couple to try. Must buy some more thinking about it, the standard spray nozzle on a Halfords can is just no good for smaller models.
Alex