what alloys

[puglove]

I would advise you to bin those spacers and get some hubcentric one like below, no spigot ones are dangerous IMO and put a lot of extra load and stress on the bolts, also below is a difference between "flat seated bolts" (needed for Peugeot wheels) and "tapered bolts" (needed for after market wheels) And yes 55 profile tyres are to big on 16's for a 306


This is a hubcentric spacer, see the extra bit? that's called a spigot, you also have one on the hub
   


This is a flat seated bolt, see how it has a big flat washer at the top? these are needed for Peugeot wheels due to the design of the wheel#

   

And this is a tapered one, you have prob got these on your current wheels, DO NOT try to fit Peugeot OE wheels with these as the tend to pull through and the wheel comes loose