2010 vw jetta - thunking or clunking sound from beneath the car when making slow sharp turn or when quick breaking; suspecting possible broken coil spring(s); is it safe to drive until I can get to dealer for repair?
There are several possibilities, and all of the ones I can think of represent significant safety hazards.
You could have a bad ball joint–which could cause a wheel assembly to separate from the car.
It could be a broken coil spring–which could penetrate a tire.
It could be bad tie rod links–which could cause you to lose steering control.
Your risk tolerance might be higher than mine, but if I had any of these possible problems, I would drive directly to a competent mechanic’s shop. There is no reason to take your 12 year old car to a dealership unless you want to pay much more for the needed repairs, but no matter where you decide to go, I strongly suggest that you do it very soon, rather than waiting.
Please let us know how you fare with the resolution of this problem.