By no means am I an expert in the art, probably better members here to comment, the mate I mention made a superb job of his Flash, think he might have got the paint from Polly Palmer (Bri-Tie) here in UK.
He used a compressor and spray gun, when I did mine I just had aerosol cans, mine came out ok ish but not as good as his.
The one factor that fell foul of was due to a stumble in the home made tent I had erected for spraying I had to do the tool box again and needed more cans, of course the colour was slightly different, not to big a thing as the toolbox as you know is not right up against anything else the same colour and nobody noticed the slight difference but me but it did and still does bug me a bit.
Would think spraying in Spain with all that sunshine should be good, here in UK getting a series of similar days weather is not the norm and it makes a difference.
I think the one thing that everyone will agree on is that preparation is the be all and end all of a good paint, if the prep is not perfect the final job wont be either
All the best with it