ok but in most cases when it's not really determiable Custum made designation then so Custom Made Silhouette. In NASCAR for example the only difference between the Chevy and Ford are the stickers the rest , body etc are identical, so unless you see some sticker or car determien from race number ther eis no point really, situation gets even worse for lower less profile series like that

in the lower racing series like dirt racing for example manufactuerers aren't involved, the workshop put some random body cos the rules require to have a slight road car look

so for such cases all this should get this designation
http://imcdb.org/vehicle_621904.html
http://imcdb.org/vehicle_638314.html
http://imcdb.org/vehicle_493632.html
http://imcdb.org/vehicle_491112.html
http://imcdb.org/vehicle_491111.html


this one perhaps Pontiac Silhouette ?
http://imcdb.org/vehicle_493637.html