The Daytona is a separate mod. I think the latest one will be included when Cascadeur1313 updates the mod after mine. Here is the separate mod: https://www.beamng.com/threads/daytona-charger.77632
That mod hasnt been updated in 2 years. and yes, it still works. although, the suspension is a little wobbly.
When was the last time you cleared your game's cache? Most graphics issues can be solved with a cache clearing.
It is basically temporary system memory. It needs to be cleared from time to time. Heres what you do. When you launch the game, it gives you 4 options. Choose "Support tools". This will pull up a 2nd menu window with 5 options. Choose "Clear Cache". This will pull up a 3rd window with 3 options. Since this is your 1st time doing it, I would do the "Deep cache cleaning". It takes longer, but it is better than the standard cache cleaning. Once it is finished. Launch the game and load in the mod. It should be fixed.
So, I don't know if you have seen this car before, but back in like 2018 or something Dodge unveiled the Hellephant and at the same time a really cool custom with that engine was showed off. It was called the Super Charger. It was a 1968, but heavily modified.1000 HP, and it looked like a brand new car despite being just a really good mod. You'd have to see pictures to do it justice. Anyway, you already have done so much, and if you only want to make the original models I understand. But if you want to make one more custom that should be mostly the same jbeam, this is a car that I think deserves it. See what you think. https://www.caranddriver.com/news/a24406690/1968-dodge-super-charger-concept-crate-hemi/