Best in-car audio: Kasey Kahne thinks Dale Jr. should 'mind his own (expletive) business'

Bristol Motor Speedway brings out the best in drivers, as tempers usually flare in the confines of 'The World's Fastest Half-Mile.' It was no different on Sunday ... even between teammates.  

Dale Earnhardt Jr. had some questions about Kasey Kahne. Kahne, however, had a suggestion for Junior. And Kevin Harvick wanted someone to remind the No. 10 what (expletive) team she's on. 

All of this - and more - in this week's edition of NASCAR Race Hub's "Radioactive."