Well i've done a few jobs on the Xantia recently and it seems to be going well. However it's paintwork is in a very sorry state. As I'm skint, living in southern Spain, paying for a garage to paint it is out of the question.... it's also the same reason why I need to paint it, because we cant afford to buy a van for the business so the Xantia is the workhorse, but doesnt give a great impression when I turn up to jobs (see picture and weep)

So I wondered if anyone has any advice? I have a friend with a compressor spray gun, but have no idea what the procedure before painting is... or during or after for that matter
Anyway any advice/recommendations greatly appreciated.