Last week had new tyres fitted by the dealer , something I would never do , normally go to local tyre fitters , when driving at speed 70 + it feels like the rear tyres are swerving from side to side , at one point it felt very unnerving. My neighbour told me the other day , more tyres take 100 miles to settle in ? Not experienced this before ? On the way back from Heathrow, 100 miles each way , they did seem ok . Do I call dealer and make a point , insist on a check up , or go with it for a bit longer ? Any advice appreciated. Previous tyres Yokohama , new on rear are Nexen , Nfera.