Thanks. I’m still learning, but I think I would use your style like this: instead of o carro é do eles. I could use o carro é do grupo. Please correct me.

That's right! Though in the first, it would be "de eles" rather than "do eles", as "do" is a contraction of "de o", and one wouldn't say "de o eles".

To add further confusion: "de eles" is usually contracted to "deles", but only if "eles" is not a subject in the statement :)