Stilshopping
The people to ask are in teh Building and Safety Dept. of your home town.

I would ask to see the building permits. I would take pictures and measurements, and then ask them to explain to you what is what. Unpermitted owner "improvements" have some unpleasant ramifications, so if you are interested in this property and want to spend the time, you can find out the truth.

I would not pay attention to what the maketing materials state about a property.
I would pay attention to what your own visual inspection of the property tells you.
For example, you might see an ad that says "move-in pristine condition" and when you see the house is it dirty and needs maintenance.
I would not try to correct the invalid description, I would just evaluate the property on what you see and make your offer accordingly.
Often in real estate I hear agents debate what a bedroom is. Some argue it needs to be a certain size, or have a closet, or have a window. The debate is kind of pointless. You as a buyer - see the house - you evauluate it - you decide which rooms will serve which purpose for YOU and nothing else really matters.
You as the buyer determine the market value.

It should also be noted that standards do change over time.
Many garages built 50 years ago are like 18' wide and 20' deep.
Today more typically a 2 car garage is like 20' wide and 20' deep.

The "truth in advertising" comes via your property inspection rights! Many times you will see, "Information deemed reliable, but not accurate" as a disclaimer.

Thanks. No, I think I could safely say that one could not park even one normal-sized car in the "garage" without tearing down a wall. (Perhaps you could squeeze a SMART car in there, and you could definitely get 2 bicycles in!) So, is there any sort of "truth in advertising" in real estate??? I'm a prospective buyer.

Still,

By your description it sounds as if you don't have a garage....not even a "one car" garage, Garage implies a space in which one could store their vehicle. Two car implies that two cars could be stored simultaneously.

If there is no room for even a single car to be parked in this space, is it a garage? We think not but possibly the city code enforcement office could clerify this for you.

Stillshopping, if it does not functionally allow 2 cars to enter and exit it is not a 2 car garage. Based on your description, it sounds like it isn't even a garage anymore. Best, Steve