First off you should always check your competitors and see what they are doing.
For the homepage I would go for something like:
Honda Forum | Acura Discussion Forums
Jeep Forum | Jeep Discussion Forums
Best practices for titles:
Keep under 70 characters, this is including spaces. (in some cases you can go as high as 90 but that's a different story for another day)
Most competitive keyword first, Google gives more authority to the words furthest left. Google bot as been proven to read left to right, similar how we do in the English language.
I don't personally use call to actions in titles most of the time - I use them in descriptions, but each his own.