There's no reason for it. Aircraft withstand huge mechanical forces against their control surfaces. Cars have only minimal forces working against them. Even power steering makes little sense in small cars. I only see it in very high end luxury cars, and then just for the prestige.

With airplanes, there was a huge amount of weight being saved in eliminating all those metal cables and linkages. With a car, there would be much less relative weight being saved by making the steering and pedals "by-wire". It will probably one day be the standard, but there are going to be a lot of concerns to overcome with the inability to steer a vehicle that has lost its power.

Not in our lifetime! Have you ever blown a fuse or have some other component go on the fritz? To simulate what would happen in a car with such a system under those circumstances, take your car up to highway speeds, take your feet of the pedals, and let go of the steering wheel. Either you will die, or you will realize that for any passenger car too small and/or inexpensive to mount redundant backup systems, some form of mechanical linkage is NECESSARY, if only for purposes of an emergency backup. Also, FBW aircraft tend to cost a few million more than a Lexus, and a good chunk of that is providing redundant backup systems. That adds weight and cost, and takes up space. Until computer technology evolves to the point where you can get something equivalent to an Intel Core i7-975EE for under $10, you won't see a system like that in any car that a normal person can afford. That said, there are some cars that have "e-throttles"... and they are hated by many for their poor throttle response and poor fault tolerance. A few cars (all of them Mercedes and Lexus) use "brake by wire"... though they have had nearly 2 million vehicles recalled to date due to brake issues and are phasing it out on those models that they haven't done so to already. There may come a time when DBW is standard on all cars, but by that time, you grandkids will be in a nursing home.

Nope. Can't see it. The reasons behind fly-by-wire in aircraft have to do in large part with the need for rapid, constant control of control surfaces on a craft which utilizes designs that are not inherently stable or which require constant, minute adjustments for proper control at high speeds. And, of course, we have electronic engine controls...though I don't really consider that a "fly-by-wire" technology use. These craft are pushing the envelope in terms of performance and effency that cars will never approach...at least, not in our foreseeable future. Yes, some "fly-by-wire" type things have been integrated into cars. Antilock brakes, some steering controls,, and so forth. But these are driven mostly by safety features, not as something required for stability control issues. An example of a high performance "fly-by-wire" case for a car would be the automatic spoiler on a Porsche 964. But beyond the safety issues...I suspect the only other reason fly-by-wire controls MIGHT be used on cars would be weight savings...if any.