I would have it looked at before you drive any further.

I've read of others who had vibration at around 50 mph and it turned out to be the driveshaft. If in fact that's what it is, you DO NOT want it snapping while you're on the road. That could be very, very, very bad. And you did mention the steering wheel vibrating...

I'm hoping for your sake it is the tires being out of balance, but that can be bad, too. I once had a tire blow out on me on Route 195. It was so out-of-alignment that the tire rubbed against the frame of the car. Luckily I was able to pull over without any further disaster.

BTW, just before that happened (for a few days or maybe a bit more) it felt like I was driving over a rumble strip all the time.

Yeah, I was an idiot for not getting it taken care of. Learn from my idiocy!

__________________
Ralph

1985 300D Turbo, CA model
248,650 miles and counting...