I have done something like this, but used a pair of cheap short (~18")HF laser levels (touching the rim) to project a beam out

Regardless of the vehicle, you need a little bit of toe in, as all the suspension bushings allow the alignment to change going down the road. If you have zero toe, then you will be toed out while actually moving. With it toed in slightly, you are actually at zero while underway.

Now that's pretty slick. I may have to test that method out on my truck.

On some front wheel drive cars require toe out duing the alignment to achieve 0 toe when driving