Gonna already assume you're a car guy with you owning a mazdaspeed 3, gonna go out on a limb and say its probably not stock lol. We're car guys, you already know theres a supercharger out there that comes with a warranty lmao. But in all realness, if the cars gonna be a toy and you're keeping the mazda then why not, only concern with the mustang is probably the mt82 in it but I can't speak on that personally. If you're getting rid of the mazda then a sports car that can double as a family car. Maybe a 10th gen civic si, a charger, G37 sedan or something along those lines. If the mazdas leaving I don't know how I feel about shoving kids in the back of a coupe, if theyre still little then its fine.