Welcome to the forum! There are a couple threads every new owner should be aware of. You can find them in the TSB and How to Article section: Index of Crossfire problems and repairs and Crossfire Documentation Collection: Click this Link

Your 28 miles is about right. On long trips in the States with speed control set at 72 mph I can squeeze 32 mile per gallon out of my Limited. In the city I get about 28 mpg.

The Crossfire came with a rubberized undercoating in the wheel wells and some of the exposed under body, but the control arms on the suspension are not coated.

I prefer the stiff ride of my cars and have actually made mine stiffer than OEM so the car is more stable while winding through turns in the mountains. Softer riding springs and shocks are available and you can use a bite more rubber in the sidewalls of the tires to help soften bumps/pot holes, but you will lose stability with the softer ride. Be aware there is not much room to play with in the front to use higher ratio tires before you start scrubbing the wheel well, however the rear is more forgiving with a bit more room. Have fun.