Winter tyres question - C63 - Size of alloy

[marcusjames]

I asked the dealer for a quote for 18" AMG alloys with winter tyres (currently have 19" on C63 Coupe). I was surprised that they came back with a quote for 17" alloys. I challenged the size (fitting over discs, not how they look visually!) but they "assured" me they will fit.

Does anyone know if that's correct.

Many thanks