A few years ago I bought the Roco 63099 VT11.5 set. I didn't buy the "Ergänzungswagen" set with 4 additional cars at the time. Does anybody know what the model number was of the Ergänzungswagen set for the Roco 63099 (model no. 63098 without sound)? I'm interested in finding it and can't find any references to it anywhere. Thanks in advance.