I haven't been to a "big" diecast convention since 2011 but it seems like the Super Diecast Convention that happens annually in Vegas has morphed into Super ToyCon to cover all things toys and collectibles...makes sense.
It looks there will be a ton of diecast activities going on, from racing to customs to autographs. Tickets are as low as $10 for a single day pass.
I'm not attending but if anyone does, let me know and I can get you an RLD shirt to wear while you're there. Otherwise, don't forget to share your photos and stories when you get back.