So, I just now realized the minecart rail track in the Grimlotts Wizarding Bank again and wondered if you can actually use it with a Minecart. Fortunately I did have a Minecart in some random chest which i could use. It actually does work and it's quite fun to ride through the bank on the railway. The thing is though that those Minecarts are to my knowledge not obtainable anymore so there is a limited amount from players who got one a long time ago. My suggestion is to just add one NPC (Goblin) to the railway area where you can buy/get a Minecart to ride through the bank as that journey is really fun. It wouldn't be much effort to implement that as is is literally just needed to add one NPC to get Minecarts as the Minecart track is working as it is. I hope I'll see a new Goblin at Grimlotts soon so that new players can also experience the journey.