Had a WN morning flight EWR- BNA & midday BNA-RDU this past Friday morning with a four hour layover - too long to sit around the airport but perhaps a little short to accomplish significant touring... But I did discover the 18 Bus. $1.80 to downtown Nashville where I did some roaming and enjoyed breakfast at Puckett's Grocery. Unfortunately the return bus scheduled an hour later was a no-show for 30 minutes and Nashville MTA for whatever reason didn't have a tracking device or communication with their airport bus (go figure) so I ended up taking a cab back, which added $30 to what otherwise could've been a $3.60 adventure. So if Nashville MTA can up their game there perhaps more WN fliers with long layovers can experience a little more of Music City. I will say I was impressed with the friendliness of people everywhere and with the vibe of downtown overall.