If you want some of these features and don't want to buy a new car with a costly option, you can get something called a Mobileye. I have one and it works well. It also reads speed limit signs and has a settable tolerance. Unfortunately it can't distinguish off-ramp speed warning signs from real speed limit signs.
Even better than that, either just on the market or almost ready for it, is an app that uses your smartphone to do these sorts of things. Presumably it could even use phones with both front and back cameras to report on what's going on behind and ahead.
I have one reservation about these things. Some of the circumstances they warn of could better be done using sound rather than imagery. While you're looking at the screen, you can't be looking at anything else. Such as front-end swing while watching the screen as you reverse. I think some portion of the reverse function should be done with audio rather than screen images.
Lastly, it's about time North American vehicle regulations allowed rearview cameras to replace the outside mirrors. I can think of no good reason not to do this, and the total fuel savings would be enormous. Not to mention cars being narrower, easier to wash etc.
