Just picked up this 2017 and notice that on light acceleration between about 30 and 40 mph, the rpm will suddenly go up 1000 rpm and quickly go back down and feel like a regular transmission upshift. This doesn't seem to happen during harder acceleration. Also, if I'm coasting down below 20 and then step on the gas I can feel a shudder. I'll have to check the fluid level but if OK, would changing the fluid do anything?