Liz took one look at this video and said, “Don’t post that.” My beautiful bride said that I shouldn’t spend 15 hours non-stop working in the shop and then get on camera right after. that. But, I couldn’t help it! I was just too excited. Here’s the update to the Mark IV Cart project. Let me know what you think with your comments, likes and shares. Stay Tuned! I’ve been hard at work in the shop and there’s another incredibly cool update coming in the next day or so. Thanks for supporting CoasterDad.com, and helping us to bring Physics, Family and Fun to kids everywhere!