I am a little behind but jumping ahead. I think I figured out what was up with W1 aka the driver. When the money drop off was first coming to light, I remember hearing that it was unclear if the person who dropped off the money knew if the package contained money.
THEORY:
I think, based on the charging documents, that the first story the driver gave to LE said he got a Manila envelope from the employee and brought it to the house. He claimed he had NO IDEA that it was money, he never opened it and no one told him. He brought the envelope to the house, unlocked the car and put it there. (The cars were kept LOCKED normally). He only found out about it Thursday, and he didn't think it was any big deal. My theory is that he was scared *****less of being either caught up in the accusations, or tracked down by a criminal (snitches and ditches etc) or just wanted to keep himself as apart from everything as he could. So he lied that he never saw the money, that the car was locked, and that he wasn't told about it by SS on Wednesday (evening is my guess).
LE discovered the text sent from SS to him on Wed, finds the text with picture of the money that driver used to show off to a friend (W2) and realizes that he lied. they re-question him and he admits he did see the money, and that he did get a text, where I guess SS gave him instructions including one that said "put the money in the car, we will leave the door unlocked".
I also believe that it is possible, not likely, but possible, that SS told him specifically that he was being held hostage, and that his (ss's) life depended on W1 delivering this and telling NO ONE, and he lied because he felt enormous guilt when SS got killed and it turned out he may have been able to save him had he called LE or told someone. Or he thought sending that text photo of the money is what got SS killed. not likely, but possible.