I've got some rust spots... about 7-8 patches of rust on about 4 panels. I tried treat the rust myself but the rust seems to have reered its ugly head again. What could I have done wrong? and would I need to do the treat again if I was to get it professionally spray painted? Or could I leave the whole thing to them?
My car is just a run about for now so even thinking about neglecting it... I know, blasphemy I hear u lot cry.
I did have the idea of putting on a Mk5 front bumper... cutting the bottom half and putting it straight onto the Mk4 but keeping the actual bumper to get the look like this

but without the clean look.. it'll still be in two sections like the Mk4.
Firstly, if I was to do that, would the bottom half fit as easily as putting on a new Mk4 lower half bumper? And how much do you think that might cost me?
Secondly, compared to changing the whole bumper to the one above, somehow sourcing the bumper from perhaps the same guy as above.
Lastly, I'd want to put my two big arse Hella Comet 450 foglights on, either on the outer side of the bumper like so

or if need be, on the inner part.

So whats the doability of the whole thing? If its slim I might end up neglecting the rust.
And whats the worst that surface rusting can lead to? I've an R reg Polo aswell.