PTAD gives us a stage with no edges, which helps us gimp and punish recoveries like Marth's and ICs, and has a couple other things. First off, a large stage is good for keeping us alive. Secondly, grabs and inhale make it easy-ish for us to get people into the cars.
Also, on the part of the stage where there's 3 platforms and the track curves upwards on the left side of the screen, when the cars come below you, only the top platform is safe. However, if you Dthrow on that platform, your opponent's hurtbox goes slightly under the platform and gets hit by the cars.
Also, Luigi's Mansion is a horrible place for us to go. I don't remember what ICs have there, but it's a great stage for them, and almost every character in the game uses the stage better than us (DK never dies, Oli is the absolute gayest thing ever there, ROB and MK have some gay **** there with Dsmash and tornado respectively, Zelda can Usmash to Dsmash, and Uair through the lower platforms, Diddy has Barrel shenanigans and ******** good combos there, etc.)
This stage being legal means I have a new perma-ban for every tourny allowing it.