I don't know if anyone reading this has or will ever buy this item, but buyer be educated. Not warned, educated. I have information to pass along that might be helpful. This is in no way a post trying to warn you against buying it. First of all, I really like it. I had to have it the moment I saw it. Finally, billboard advertising something that fits my theme. However. Not being a robust train man of knowledge, I have no idea what they put under it. It looks like some sort of attaching point. It's just a plastic hose or nozzle looking thing attached with a rivet of some sort to a metal hanger that runs almost the length of the under belly. Not only do I not know what it is, it is danger close to the rails. I tested it at a very low speed, intentionally running it across switch track after switch track and you guessed it, it hit one face on. Caused the switch to activate and both it's rear end and the front end of the car behind it, headed for track 2. That's why I test them at slow speeds. Imagine what would have happened if I had been up to speed.
I removed the shell, four screws irritatingly close to the trucks. The shelf mechanism was held on by bendable clips at each end. Bent the clips, removed the shelf and thus the mystery detail piece. As I said the screws were difficult to get too but not impossible as the trucks are attached on the inside of the shell via a shaft held in place by one of the C-shaped clips you need a special tool to remove. Nice idea actually. The trucks are using an old style magnetic system I saw only once on a Sunoco tanker that is being sold on Ebay by anyone and everyone who has one. You don't have to clip piece on the finger side of the coupler to push down or push backward to release the coupler. You have to reach under the car, impossible, grab the back of the truck piece and pull down. Again, not possible without taking the car off the track. So, we are left to hook up the car the analog way. Using our 5 digit hand coupler you lift up and set the two coupler together fully closed.
Finally, the couplers, the front one (the one on the end where the brake wheel is installed), shuts hard but shuts. The rear coupler, on mine, you have to slam it shut or to save buying a new one, use one of your 5 digits to shut it.