It's certainly possible and I'm hoping this is the case because if so it could lead to the solving of this case. If warming up the vehicle was Hania's normal routine, this does seem quite likely.
What gets me is that he was able to disappear so completely. Hania was heard screaming, so authorities were contacted immediately, yet the guy gets away. I sure hope they are doing a search of every garage within a certain number of miles of wherever that photo was taken.
This is what always amazes me these days. There is saturation CCTV everywhere, people's homes, stores, highways, dash cams, etc., not to mention knowing where everyone's location is through mobile phones pinging everywhere. Yet still people disappear without trace even with all this modern technology. Also criminals don't seem to care anymore, whatever crime they commit they don't seemed bothered if they get caught or not. Its frightening really when you think about it.