Handle "banned" cars if they are selected

[Bjorn248]

Certain cars are banned from competition only in street class, other cars are banned outright. Figure out a way to display useful information to the user if they select a banned car.

[Bjorn248]

@ejleitzke if you have any ideas for how to address this issue feel free to post them here!

[ejleitzke]

Wondering if there should be an explicit warning if that car model is selected, or only if it is selected in stock form? So for example if you select a Ford Fiesta there would maybe be an extra page that says something to the effect of "PLEASE READ! The SCCA has identified your car as a potential risk and is NOT ELIGIBLE in STOCK FORM. To compete with your selected vehicle, you must upgrade your suspension." I am pretty sure the ban only exists for cars that will topple so I think that would cover it? We could potentially get more granular if we decided to do something like showing eligible classes on that page instead but that may be over complicating it. My 2 cents! Whatcha think?