I just sent off an email to have some louvered vents for this car made:
Bill Lane of http://www.3dmodeltech.com/ announced this morning he'll be offering these on an "as ordered" basis (no stocks on hand). He's shown the vents he's made in S scale on the ACL-SAL-SCL Yahoo forum and says he can make them in O as well, he's going to test to see if he can make them i HO too.
From what he says on his site, he's going whole-hog on this and can make things from Solidworks ".STL" files that the customer provides. I'm going to have to look into Solidworks!