Car transporter are a common sight in freight trains here in Europe and pretty much elsewhere. Without them, it would be impossible to move large amounts of newly produced cars from the factories to the ports, where the cars are shipped all around the globe.
Most of the time, special double-decked freight wagons are used for these duties. They are usually paired together by means of a rigid coupling between them.
Other sub-classes of these types may feature only one middle axle, others are covered up and consist of up to four individual wagons, which are permanently coupled together.
Pictured below with some freshly manufactured cars! (Credit: Cars by Thomas R.)
About the moc:
Custom parts: MR52-ZZ ball bearings, rubber bands
Minimal radius: R104
It should be able to hold up quite a good amount of cars. Be aware of the slanted sections and overall height restrictions on the lower deck.
Additional info/disclaimer: Due to the long wheelbase, each wagon features a steering mechanism in order to minimise the derailments. Just cause it worked fine during my testing, it doesn’t necessarily mean that it will work with you! This is unfortunately a rather common problem with two-axled wagons in this scale.
Feel free to repaint the wagons to your own liking, feedback/criticism is much appreciated. Have fun!