Thank the Seers for rampant retail.
Most of the mages he knew let their principles slide when it came to coffee. Him? Twenty-four hour stores. It's all part of Their Plan. Buy this, buy that, the shackles of debt and conditioning to Keep Up With The Joneses.
The cold air of the store had woken him up. He'd almost fallen asleep. The droning of the car, the buzzing of words. It was so past bedtime. But not yet. In the newly aquired plastic, yes plastic not paper save the trees, bag was an assortment of scissors, razors, and clippers. And quart sized Zip-loc freezer bags. Don't forget the bags. Okay, he'd forgotten the bags, but he'd gone back and gotten them before leaving so it Didn't Really Count.
Stepping out, he waited for the car to swing back around and pick him up. That's the plan. Step one: Drop the Phantasm. Presto, the car was a different car, and any blood on it shattered and left behind with the forgotten threads of the illusion. Step two: Drop off and Drive. Keep the car in motion, doing circuits around the parking lot.
By now, they'd have covered Bonnie with the coat he'd left behind. Soon, they'd move on to the Next Part of The Plan.
Planning, yo. It's A Thing.