Adding that much weight behind the rear axle will cause the front to lift a bit. When the front lifts, the wheel alignment changes and your tires will wear unevenly. Once the rear weight is removed, the front end will go back into alignment.

 

600 pounds will put a strain on the metal of your frame. You'll need to beef up the mounts. Yes, it will mess with your steering too. While alignment can be a problem, I'd be more concerned with handling in the rain and snow. Get your self a trailer big enough to haul the bike and maybe a little more. Possibly some racks for fuel and such.

I swap cars like some people swap comfy shoes. I currently have 4 plus a bike. I've had my 5X10 tilt bed for 30+ years as it's just so handy to have. Newer ones have a ramp built in. Mines a tilt bed with a hand winch I added to pull tings onto it. Get one a little bigger and you'll use it a lot.