Joe,
I agree entirely that we will always have some of each, but I don't think every dealership will have all 3 anytime soon.
Some dealers are going all in on online, some are going hybrid and some are going full traditional.
I'm working with a store that already went commission free, got rid of sales people, sells at invoice price and is ready to do full transactions online.
I wouldn't suggest we're going full online anytime soon, but I certainly don't think that's for the reasons being stated in this thread.
I think consumers are ready for this (at least a subset are) and I believe that this subset is growing steadily.
eCommerce trends are up across the board and consumers are spending more and more online - it's a natural progression.
Car dealers may just have to stop selling cars they way they're used to doing it.
For a one price store this is much easier.
- here's the car
- here's the price
- here are the financing options
- here's the after sale products
- here's the bill of sale
That whole process can be done online without sales department involvement (legality pending) and that seems to be the way forward.
In the meantime, I think Live Chat and BDCs have a huge opportunity to improve this process and help customers along.
Soon enough buying your next car will be as easy as booking a service appointment online 
