I have done more road trips then my family likes. They don't want to do it anymore. I like my trucks or SUV (4 runner) for this. Done them in cars too when I was in my 20s including rentals. I am glad no one mentioned fun and must handle well because most of us have been there and done that. Dennis is absolutely correct, comfort, but not always luxury. Set cruise and enjoy what this great country has to offer and don't sweat the car too much. I know we are all car guys and are always excited to get out for a drive, long or short, just like Higgins is doing right now. Heck, I get excited just driving to San Diego by myself next weekend for a simple camping trip with old friends. I will take the Cayman this time.
Do it in an SUV just in case if there's a bit of dirt on the road. You'll need the ground clearance and 4WD