Shereef,
It's actually a great out-of-box solution, the tricky part is creating the CRM integration in ADF format more than anything. And of course there aren't any preset scripts built in specific to automotive, but that opens a whole other series of process issues.
On one hand, you can take a product like ContactAtOnce or Chat24 that's fully integrated into the automotive vertical, but sacrifice design and advertising potential. Alternatively, you can use a product like ActivaLive and have complete flexibility but must invest money into custom development so it can communicate with the various automotive CRM systems. Obviously there's workarounds to both systems. 
I think the decision comes down to the goals, and digital advertising dealers are doing. I agree that average dealers would be better fitted with an integrated solution, but dealers that "get" live chat, and looking to drive more leads should also consider integration into advertising like display, widgets, apps and more. We do a lot of that at Cuneo for various dealers and have found some success with it.\
Benny,
Something like Facebook chat has two components. The design, and technology. From a technology standpoint, those modules can be very load intensive. It has the potential to slow websites down, or break things. As most 3rd party providers are built as template systems it can be a daunting undertaking from a development standpoint to implement it... especially when most can't even get basic "tags" in place to track search, display, or analytics.
Also, while I completely agree that things popping up is annoying and alarming-- they tend to perform... especially if it's user initiated or based off the behavior (ex: someone's looked at 12 vehicles but not called or submitted a lead. Or been on the same contact page for over 5 minutes). Making it look seamless, pretty, and perform is the challenge you touched on.
There's also the potential that network administrators have blocks in place to prevent that type of heavy scripting. As many people use live chat at work that could have a detrimental effect on results.
The technology is definitely there, though. Good idea.
