An auto enthusiast or an autosessive is a person who is obsessed with his car. Auto enthusiasts love their cars so much that they like to spend most of their spare time with their cars. Nothing pleases them more than talking about cars. There are communities for these people, where they get a chance to share their ideas with other like-minded people.
There's a well known saying that "Birds of a feather flock together". In every sphere of society we find people, having common interests, creating their own groups. Be it a baseball game or getting together for a concert or a ballet class, having a common ground is important to individuals and the society itself.
Earlier the people who loved cars, got together and formed auto clubs to have discussions on the updated information on automobiles.