None of the information on there adds up, which is upsetting.
Phone was left at friends, car was towed, he bought traveling items but car was towed, he left without his phone but left it at friend's house? Things like this are upsetting because then it makes it seem like this was intentional by someone...
It's a huge red flag to me he hasn't even called work. If he did travel, wouldn't he have called someone ahead of time?? Even though he left his phone at a friend's, you can still call the phone company and ask the last few texts/calls to see if anything comes up, and perhaps locate the calls for the previous hours before he disappeared for clues..
I hope he isn't in danger, and you all find him! I will keep a look out... Where did he live, city/state wise?