Do i need appoontment to have auto starter installed..or just show up?

Do not do it it will be a wireing nightmare in about 3 to 6 mounths

I would call for a appointment to have it done

I would call ahead to see how busy they are.

You can just show up but they will probably schedule an appointment to put it in then. But if they're not busy they might be able to start today but it takes several hours.