Mika didn't even hear Dean walking up on the gravel of the junkyard to signal his return to her and Bobby, she was so focused and stumped as to why after everything she had tried, nothing was fixing her beloved car. She had her music on and as Dean stared, he would have seen her legs move every now and then to the beat. She had some grease on her face and hands which was of no surprise all things considered, leaning right into her car. 

When Dean spoke up asking if she needed a hand, she paused what she was doing and smiled brightly at the familiar sound of his voice. Standing up straight she turned round as she grabbed the rag to wipe her hands as best as possible and took in his face before running to him where she proceeded to glomp him with very little warning. "Dean you're back!" she beamed, hugging him tightly. "And to answer youre question yeah, I'm utterly stumped this time round, she just won't start and I've tried pretty much everything" she explained, pulling back from him a bit. 

She wanted to ask how he got away from his dad's hunt workload but her sensible side told her it could wait. For now she just wanted to enjoy that he came back for a visit and not worry about the more depressing questions and answers. She didn't even know if John knew if she was her, or if he still thought she was Kenzi but the moment she saw Dean's face that constant curiosity just vanished. 

Letting go of Dean now she realised she still had a hold of him, she started walking back to her car to show him the current state of it to see if he really could figure out what she couldn't. "I've asked Bobby constantly to keep checking she's running alright but has he? No. It's been so busy back here on the phones and stuff that neither of us have had the opportunity to keep the maintenance up on her these last few weeks." she explained. "I thought it was just a dead battery at first but ruled that out instantly" she said to him so he could at least save time in not checking that.