so check this.. I bought 4 new Nexen N5000 tires, balanced them and did an Alignment, not to mention filled the air with Nitrogen, not O2.... WOWWWWW.. I couldnt believe it!!!! The car drives like SILK! Everyone that i drives says, WOW I cant believe how smooth this car drives. It drives better that my cuzins BMW 325i.. When I drive on the freeway I hit 100mph so easy I dont even realize it. Thats how smooth it is.. SO try this if you have shaking. By the way, if you have after market rims, your going to need inserts to stop the shaking. !!!!!