Scantlin says, when she woke up Monday and noticed her Honda Pilot had vanished from her home -- she immediately suspected Wes. Jessica says she texted Wes' manager to demand the singer return the vehicle asap -- and 6 hours later he texted back the exact location of her wheels. She says the manager also texted, "Wes didn't take your car". According to Jessica, cops impounded the Pilot to have it tested for prints -- but she's "100% sure it's Wes" because the windows weren't broken ... and she claims it's likely he has a spare key. She says she also recieved texts from Wes afterwards:"Learn" -- and the other ... "You can't hide. I hope you have a shovel."