My front wheels are suddenly out of alignment. I

if the shaking starts at around 30 mph have a wheel alignment done as it indicates a castor wobble problem
have the front end and suspension checked for worn steering joints , ball joints and wheel bearings

There are numerous things that may cause this issue. Start with tire pressure at proper amount on all wheels. Next, have the front end steering/suspension checked for loose/worn parts. An alignment may be needed as well.

Get the four wheel alignment if you heave never had it done. Be aware that on the rear the adjuster bolts may jammed with rust. On the front, the ball joints, rod ends and strut bolts need to be on good condition.

This is a common problem. The last time the aligned it the may have bumped the steering wheel and when they aligned it and tightened everything back up it was off center. The next time you get it aligned make them aware and they'll straighten it up for ya.

while the wheel bearings still feel tight they are the cause of your problem, after a collision most cars suffer from this problem depending on the speed of the accident the forces encountered during a sudden stop causes intense stress and fatigue on the bearings

NEED TO LET A BODY SHOP CHECK OUT FRONT UNIBODY STRUCTURE FOR DAMAGE WHEN YOU HAD A FRONT END COLLISION. IF FRONT STRUCTURE BEND OR DAMAGED. THE FRONT BUMPER AND HEADLIGHTS FRONT WHEEL ALIGNMENT GOING TO BE OFF.SOUND LIKE FRONT END COLLISION IMPACT DAMAGED THE FRONT UNIBODY STRUCTURE.

You Have a camber problem. Check the front control arms. Sometimes there are adjustment for the control arms. Be aware that you will need to have the vehicle on a wheel alignment machine to get accurate results.

Somethjng is not right with the front suspension of you car. Might be a bent part, something is wear out, or loose. This is dangerous and your tire will create bias, so will cost you more. This car needs a front suspension inspection, and alignment check. We do this service at our dealership 4 wheel alignment $75. GM charge $75 for front wheel alignment, parts extra. Any suspension repair shop can give you a good answer.

Usually that happens if the body was wrongly assembled or somehow got askew (most often after heavy collision; but, you have said there was none).

Front end need to be checked. checked shocks and stabilizer links.
check damper shock. Check the tie rods. They had come loose, causing the wheels have excessive play and vibrate. Be aware that they will not balance tires or give a front end alignment if the tie rods are the culprit. They must be replaced first, otherwise the alignment will only hold until the first time you turn the wheel...which could be 5 seconds after you get in the car. Good luck.