my car over the past couple days has started shaking more and more when i'm on the freeway. at first it was barely noticeable but now i don't like driving much above 50 because the shaking gets pretty bad. i've checked for the obvious flat/bubbled tire or wheel not bolted down securely but everything looks pretty normal. i'll try jacking it up and checking each wheel when i go to my parents house tonite. anything in particular i should be looking for?
the shaking increases with speed and is not related to rpm or anything. car still drives straight and doesn't drift. at lower speeds the shaking feels like the car's being pulled side to side slightly.