Which 15mm wheels spacers will fit on the rear?

[Aquavalver]

I bought some 15mm wheels spacers back in December and thought I'd fit one to the rear and one to the front and then judge which end to fit them on and then going by that decide what size to get for the other end. I went to fit them to the rear, but found they would not fit flush against the face off the brake drum as the centre of the spacers taper in at the front edge and the hub centres of the car stick out a fair way and more than the front. Anyway I fitted them to the front and got 20mm bolt-on spacers to the rears.

I bought some coilers and and going to get them fitted next weekend, but when I went to the GTI spring festival with a fair few things to sell, the weight of it lowered the car and I bought that the tyres had been rubbing a little on the rear arches when going over bumps. Of course once the coilovers are on, the car will be lower, so the rubbing is more likely to happen which is why I'm after 15mm spacers again, but some that will actually fit! Which ones have you used which will fit the rears?

Thanks for any help!