If I thought someone was bullshitting me I probably wouldn't buy anything from them...
The fact that they're not telling you the truth about the vehicle they're selling proves one of two things: 1.) they're stupid, and they probably didn't take care of the car, or 2.) they don't have a problem with lying, which means they might be lying about other things (maintenance, condition of the vehicle, accidents, etc.).
Oh well though, seems like you're happy with it, so I guess that's all that matters, right?