ok guys, on my sisters 05' Stratus the fuel gauge fluxuates when its around quarter of a tank. when you first start it up when it has around .25 of a tank left, the gauge will go up to the half mark and then after about 15 min. of driving it will go back down to .25 of a tank. the car has 32k on it and only have 4k left on the warranty so i need to know if this is just how it reads it or if its a problem with the fuel sending unit.