Before neons, this game should get more stock parts available for some cars (2010 street and perf camaro do not have the stock hood, challenger does not have the stock spoiler on street and dirt spec), they should add fenders, adjustable wheel size and offset, add wheel and calliper paint options, add tinted windows, ride height adjustment, the ability to design your own stickers, to name a few things.
It's not an issue of if the players do or don't want them, it's an issue with licensing. I am pretty sure that manufacturers do not want neon's put on their cars to ruin the reputation of their car... That and neon's went out of style a long time ago and The Crew is set in the year 2020, where pretty much nobody even puts neon's on their cars (except the people who have been living under a rock their whole lives).