Also, do you find any locations with WMMT3/3DX/3DX+ with a working card reader? I have two of my local arcades with WMMT3DX+ with a working card reader. The first one have 4-player VS and new cards available, meanwhile the second one only have 1-player and new cards are not in stock.
I had documented a few back in the day, but I understand some arcade operators dont have the resources and turn them off to reduce future problems popping up on the machines. If a venue is still supplying cards it is likely run by someone who is passionate about the series and is keeping up with the maintenance. Someone like Sebass over at @ Arcade replay stockton on YT.
If you already knew that the card reader isn't functional, you shouldn't have played it (unless you didn't notice), unless you're here JUST for the 10 Outrun mode.