I'm enjoying the new D15 Custom Classic configurations, but I can't help but feel that they could be improved with a little extra splash of chrome with the wheels. Unfortunately, the 15x9 classic steel wheels (maroon truck) cannot have hubcaps equipped, while the 15x7 classic steel wheels (blue truck) have a hard time filling out the fenders even with the largest standard tire equipped. It's also difficult to get the steel wheels/chrome hubcaps look going on any that has significantly larger wheels in the rear than in the front.: If you want the Gavril ridged hubcaps, you have to go all the way down to the 15x6 classic steel wheels: So, I'd like to suggest that a handful of smaller chrome hubcaps make their way up onto the 15x9 classic steel wheels. The center caps, dog dishes, small smoothies, and Gavril ridged hubcaps would add customization flexibility, eventually improving the prospects for budget hot rods and drag cars in career mode.
What mod? Everything you see above has been assembled with parts available in the game itself. That's the problem. There aren't any hubcaps available for the 15x9 classic steel wheels.