The Disappearance of Tara Lynn Grant

On February 14, 2007, Stephen Grant walked into Macomb County Sheriff's Office a little before 11 a.m. He told the desk sergeant that he wanted to report his wife Tara missing. Turning to the deputy manning the desk with him, the sergeant asked him to call detective Bill Hughes, a 20-year veteran in the police force, to the lobby. Hughes invited Stephen into his office, and sat silently as Stephen immediately began rambling on about Tara Lynn Grant's disappearance.
He stated that Tara had gotten home late on February 9 because of a snow storm. He revealed that he had drunk a couple of beers before she arrived, and that they had argued on the phone earlier in the evening because she had changed her travel plans. She had stated that she would be flying out on Sunday instead of Monday, and this had him bent all out of shape. He stated that she walked into the house wearing her ear buds, and didn't immediately respond to his greeting.
This riled him up, and they resumed their argument soon after. After about 20 minutes of arguing, he said he overheard her talking to someone on her phone, asking them to pick her up and that she would be out in a minute. He had no idea who was on the other side of the call, but he assumed it was the car service she usually hired to take her to the airport. As she left, he said, she told him, "Don't forget to get the car to the dealership Monday to get the dent fixed." He then saw her enter a dark sedan parked at the end of the driveway.
That was the last time he saw her. What happened to Tara Lynn Grant?