I've recently had to replace a headlight washer jet cover and spray it myself. Ive finished with the paint and iv coated it with loads of layers of lacquer, but i just cant seem to get the shiny finish. Any suggestions? I've put about 5 layers of lacquer on now but it doesn't look shiny at all...
The new part i've resprayed on the left - Original cap sprayed from factory on the right

Looks to me that you've painted over fresh lacquer! you did put the paint of first didn't you?
Contrary to what you may have already heard, do not re flat paint or lacquer between coats, it just increases the chances of something going wrong!
Lacquer should only be applied after the basecoat has become touch dry, 10 to 15 mins is a good time after the last coat of colour
Thom