If you’re looking to start out in motor racing and you’ve got the cash, there’s a number of exotic automakers that offer their own spec racing series.
Ferrari has its Challenge series,
Lamborghini the Super Trofeo,
Porsche various Carrera Cups and
Maserati runs its own Trofeo as well. Each of these championships runs identical machinery derived from their respective road-going sportscars, but upgraded to competition specifications.