What can cause a steering wheel to shake and vibrate?
As others have said, it’s usually down to wheel alignment or balance and is usually noticeable after a tyre change if the change wasn’t properly handled. Occasionally this can also be caused by one of the weights placed on the wheel by the garage to balance it suddenly detaching (though this is rare).However, if you notice any sudden change, I’d certainly advise you to stop IMMEDIATELY and check what’s wrong.One day, a few days after a tyre change, my steering started to noticeably start wobbling badly as I was overtaking someone at 70Mph on the motorway. Due to the suddenness and violence of the wobble, I assumed one of the lead balances had suddenly come off and I decided to pull in immediately to the hard shoulder but as I was pulling in below 40 Mph, there was an almighty bang and shudder in the car and I found myself watching the left wheel of the car running away into the distance - luckily off the motorway, into a field.I managed to steer onto the hard shoulder with the car running on 3 wheels and the brake disk of the missing wheel - it turns out that the garage hadn’t tightened the nuts well enough and they came loose and out mid drive.Motorway recovery eventually retrieved the wheel for me and as the tyre garage was within a mile of the motorway (and I was quite close to that junction) they drove me there with my car on their flatbed truck. The manager of the garage went ashen when I explained what had happened but as the only damage was an almost unnoticeable large but gentle dent in the bodywork where the wheel had hit as it went off on its bid for freedom, they were able to fix it with new nuts and get me back on the road quickly.Extremely scary experience though. Modern tyre garages tend to do a final tighten with a wrench for safety if they’ve used the compressed air spanner - something that hadn’t happened in my case. I now always ensure this is done before I leave the premises.
How do you fix a CD player in a car that keeps ejecting disks?
If you have never fixed any electronics, you probably don't. You are going to have to buy a new one. There's a chance that it's just a bad part, but the parts are probably not available. I have 25 years of electronics repair and I would just buy a new one.
Can a modern car engine fit inside an old car? If it does, can it work?
Fitting the engine in won’t be a problem. As you noted, older cars are larger with plenty of space in the engine bay. The problem you’ll have is making the newer engine work in the older car. Newer cars have multiple sensors, computers, and subsystems for traction and stability controls, transmission controls, anti-lock braking, and in some Cadillacs, even electronic controls for the shock absorbers.The bummer part is that if you remove some or all of these subsystems, the engine management system may not function properly to run the engine normally.A better option for your purpose would be to buy what is called a “crate motor”, which is a motor specifically designed to be used in multiple types of vehicles. GM makes crate motors, and sells them through Chevrolet dealerships. Here’s one that might interest you:LSA Crate Engine - Race EngineThe LSA V8 is the same motor used in the Cadillac CTS-V, and if you add the “connect and cruise” option, it would be relatively easy to drop this motor into an older car.