Yes, that's true, you can do whatever pleases you, but you asked for the opinions of other people, and this is my opinion. If I was going to spend my limited vehicle-making time on a police car, I would want it to be a plausible one. For me, one of the appeals of cop cars is that they're part of a fleet, and using a car that isn't recognizable as a police car -- unless it's extremely powerful or otherwise curious -- isn't something I would go for.
I'm not hostile toward the idea.
Don't look at it as "no, don't do that thing you're interested in, I hate it"
instead, think "if you're choosing between this and a different project of yours, I'd prefer to see the other thing first"
Poll