Owing a car isn't a criteria for attracting the right investors, clients or people to yourself. I'm curious on why you think so.
Do you live in developed countries? if yes, nothing surprise you can think like that because having car in developed countries is a common thing.
If you live in developing countries, do you have a car? there's a difference between other people perspective to you when you have a car or not. Owning a car will make you look successful.
I agree with him, owning a car do attract people to you, but in the end it's all about your skill to convince the clients to make a deal.