What causes high rolling resistance in a car?

My Infiniti FX35 seems to have high rolling resistance. By which I mean it loses speed and momentum very quickly as soon as you let off the throttle. Even when going downhill I find myself needing to press the accelerator or else the car loses momentum very quickly.

My brother's 2012 Honda Accord behaves in a very different fashion, as the second you let off the brake the car rolls at like 5-10 mph without even touching the gas. Once I'm up to speed I only need a very small application on the accelerator to maintain that speed. If anything I need to apply the brakes significantly more in that car as the speed can sometimes increase significantly on slight downhill slopes even without any input on the accelerator. The two cars behave very differently in this aspect.

What causes high rolling resistance?

Can you put premium gas in a 2017 Honda Accord LX?

So my Honda Accord 2017 LX takes regular gas, but some people, including the car salesman are telling me that I can really put whatever gas I wish.

I heard that adding premium is better for your engine?

Also if I were to add premium, is it better to have to fill up once I'm completely empty or can I still add premium gas when a bit of regular gas is already in the tank? Will there be trouble if I mixed up the gas?

Will sheet metal screws hold a license plate?

I'm selling my 2006 Honda Accord soon, and the front license plate was stolen or fell off. The replacement bracket costs $40, there are no aftermarket equivalent, and is a pain in the --- to install - I know because the same thing happened a few years ago.

So I just bought a universal license plate holder, and want to drill into the bumper. Can I just use sheet metal screws (pointy tips), will they hold up? Or self-drilling zinc? Or I have to use fasteners, or toggle bolt? Etc.

My family says that I need a new car because my current car is old and beat up

I currently drive and have been driving a used 2004 Honda Accord for five years now. I have only needed it to be repaired six times. My family thinks I need a new car as soon as possible, but my car is enough for what I do. I myself have also been thinking about a new car, but I'm not a car person. I'm thinking 30k and under would be a good price range for a new car. Any suggestions?

Which car is better?

Toyota Camry
Honda Accord

Toyota seems #1 in safety but all my friends seem to like Honda. Is Honda just more "stylish" or is it actually more reliable?

Also debating Honda HRV or Toyota CHR (new models).