It was most likely there was something about the car that made you feel good. As the owner you are in a much better position to convey the emotional information about your home than any agent. Be sure that you let buyers know about these things. Visualize and jot down notes about all the little things that make your house special. Mention these items in your advertising.
People do it every day of the week - all over the country.
Basically what an agent can do that you can't is to place your home in the Multiple Listing Service. In some areas of the country even that barrier is coming down. Several MLS associations have been taken to court and lost for not allowing access to the general public recently. The common denominator of most of these properties is that the owners have signed an agreement to pay a fat commission to the listing broker if the home sells for the privelege of having their home put in their computer database. The brokers have an agreement to share the huge commission if an agent from another office sells the home.