There nothing magic about it just because it's a car. It's a tiny car and car haulers are designed to fit full-size pickups. In fact, I used a 16' utility trailer up until the time I needed to put a full-size pickup on it. The utility trailer I use to borrow was made out of 3x4 3/16" angle and was mostly used for an old Allis Chalmers.
There's no concern with the weight balance. The car is already heavier in the front. You would have no problem getting 300# on the tongue. The single axle doesn't matter--a tandem axle has an equalizer bar that pivots in one spot--unless you have torflex axles. This isn't a 5x8 lawn mower trailer with a 2,000# axle.
The sides are 12" high on some of those. My Honda door is 11" off the ground. I would cut a piece of railing down to 10" (or whatever) in that spot--or have it done at a welding shop. If it's really low, car haulers have fenders too.
The benefits of a single axle is that it's easier to make sharp turns and back up into tight spots because the tires don't scrub. You don't need 7,000# worth of axles or 16-18' worth of trailer. You don't need an extra 800# of trailer. Big Tex has a 12' tandem axle car hauler that can be gotten 12' long. It weight 1,680#. That wouldn't be a bad choice.
Renting one is an option, of course. U-Haul trailers weigh 2,200# and you need a 3,500# car to pull it with--minumum. They also require the towing vehicle to be 80% of the weight of the combined load. I don't think a 2wd Ranger fits either category. Make sure your low clearance car doesn't hit something while loading it too. That makes the drop gate of the 6x12 inviting. My trailer has a dove-tailed rear which makes loading low things easier so look for that in a car hauler.
Cheapest bet is to search the fields for something to make one out of.