Hmmm, I agree with just evolving story, and the functional car bit. I would not agree about the weapons however...
It would be nice to see SOME new weapons, not a lot, and not from earth. If there's anyway to get 'new' weapons, bring back tho old ones... Wait, they did most of that... except that Grenade launcher from HL1.
I think it would be great if they combined human weapons with combine, a "mixture" of technology to add a little originality. That's just my opinion. Probably a bad idea.