Andrew is on the case with a sound package for the Centurion as he wants that model to sound right. As you say he has to look at production costs very carefully and sound packages can come expensive for small scale producers. Most of the electronics firms Andrew deals with want orders by the the thousands. Andrew is not a mainstream producer so gets penalised for small volume production runs from suppliers. However he tells me he has a few irons in the fire re a sound package with correct Centurion engine sound. Once again an ongoing project in this Models development. I will keep everyone updated as and when I get more info.