Dip in Driveway causing car to bottom out - How to bridge the gap?
It looks like the dip is there for drainage, so you can't fill it in - otherwise water from the street would flood your garage every time it rained!

My suggestion would be to get hold of a set of "bridging ladders", as used by off-roaders to bridge gullies - they look very similar to the grids covering the drain in your photo, but thicker, wider and stronger to hold the weight of a car. You could probably bolt them down if necessary to stop them moving, or just store them loose in the garage, depending on how often you need to get the car through.