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.
Add CV joint to the list and all @VDCdriver said applies to this also.