First check to see if there is a cat under your hood.
If that isn't it then your starter pinion has probably failed to engage in the flywheel ring gear. That can come from a bad pinion, a loose starter or most usually a bad ring gear. You can test this yourself without even using a wrench. If the car screams at you, stop cranking, pop the hood and turn the engine a few degrees by hand (I didn't say it would be easy, just that you wouldn't need a tool).
By turning the engine those few degrees your pinion may find good teeth on the ring gear and start. If not, it probably isn't the ring gear since they usually only go bad in spots...not to say it isn't the ring gear going really bad but, if it cranks and starts after you turn it you can be pretty sure that you'll need a new flywheel.
screeching is almost always a loose belt.
When a 1996 Jetta is not receiving any spark a diagnostic test should be done to troubleshoot the ignition system. Several problems can cause no spark such as spark plugs, the ignition coil, distributor, or spark plug wires.
The radio time would stay on if you had the keys in the ignition but the ignition was only turned halfway.
If is probably an old fan belt that is slipping and causing a screeching noise. Check the one that is attached to your AC or alternator and replace it if necessary.
Headlights run off the battery not the ignition...
Bad CV joints
Yes the 2006 Jetta has an immobilizer, there is a chip in the key fob which is activated by radio signals when inserted in ignition. It can cause grief when the key is not read properly ,your car will start run for 2 seconds then quit .
whst causes screeching sound when i turn the key in my car?
The ignition module will send a signal when the key is turned. If the module is no good the signal is not sent to the other ignition parts,thus not allowing the car to start
bad battery. bad ignition switch bad solenoid or the new starter is faulty,has been known to happen
There is a short somewhere in the ignition system causing the fuse to burn out. Start by replacing the ignition switch to see if that helps.
good chance the fan belt is slipping when driving may need tightning up this wouold cause a screeching noise.