Car seller scammers

I've been in contact with several seller's this week where I was interested and asked them to send an actual video of the cars to be sure it's accurate before I travel far. Three of them said they would send it when they get where the car was but never did. Then by the next day the cars showed "unavailable ". The other sellers just never responded back. It doesn't make sense that if you have someone interested that you would all of a sudden mark it as "unavailable " without telling them what happened. I find it strange that your sellers are so interested in selling cash cars until you start asking for proof of things. There was another seller who post a photo of a 4dr vehicle but the description said a 2dr coupe. When I brought it up he said the app made a mistake then went back and changed it.