Stress on front fork from car transport It's often easier to transport a bike in the back seat of a car with the front wheel off, rather than setting up the bike rack. I've noticed that, due to the way the car seats are built, there's often unequal stress on the fork. Do I need to be concerned with this, over the course of a few hours on the road, or is this a nonissue? 

The bike I most often transport like this has a steel fork, although I have a bike with an aluminum fork I put in the back seat every so often.
How much unusual stress are you talking about?  The weight of the bike all on one leg of the fork?  Or the weight of a really large person leaning back against the fork?

If it's just the weight of the bike leaning "wrong" on the fork, I wouldn't worry about it.  That fork leg is built to handle a lot more stress than that in normal riding.

If it's worrying you, you could always pick up a cheap hub and quick-release skewer and put that into the front fork when carrying the bike in the car like that.  That way the stresses on the fork would be shared on both sides and much more match up what happens when you're riding.