Go to the dealer and ask for prices of the 4.8is rear silencers ,you will find that they are much cheaper than the 4.6is(no idea why..they just are !).Price here in Europe and they come from USA is around USD 950.00,cheaper than what some are trying to sell used!
thats how I bought mine...

Give the dealer these numbers and get a price
B18.10.7.529.453
B18.10.7.529.454