If an ammeter grounds into the instrument cluster, have fun. Those little cork donuts aren't much of an insulator IIRC.

I'm not a fan of ammeters in cars. If someone wants to run them, great... it's their car. There are plenty of people that run down folks that dislike ammeters and normally have comments similar to "Have you ever seen one cause an issue like this...." why yes I have .

All good, pick your part, pay your money!