I happen to be shopping for a 24' enclosed car hauler now. I have a 16' equipment trailer that I have had since 2000 and it has been to both coasts and the gulf many, many times with no problems. I have hauled cars, trucks, boat trailers w/boat up on the deck and even my 2 small dozers.
The problem that I have found is that trailer manufactures are bought, sold, open and closed with regularity so the brand or model that served others well in the past isn't the same one produced today. This means that you have to closely inspect each trailer to determine what you are getting. Trailer manufactures are close cousins to RV builders and we all know the quality that they produce.
If I were the OP I would select:
tandem axles, brakes on both (a single axle in that size trailer will be quickly overloaded)
I could go with spring or torsion axles, many prefer torsion
side door
a wedge front can be good but watch for too short of a tongue
"Advantech", "Drymax" or equivalent 3/4" floor along with an undercoated frame to prevent rust, watch out for a lightly painted frame
decent interior height, nothing worse than bending over just to walk around in your trailer.
when shopping check the construction specs:
floor cross members and side posts 16" on center. cheap trailers will use 24" ctc. Z posts are cheapest, T posts better, tube posts are best. same with roof frames
cheap trailers will use luan for interior paneling, good ones will use 3/8" ply
.030" siding, cheap trailers will use .024"
one piece roof
watch for cheap screws holding the skin, they will start to rust in a few years, stainless is better, "screwless" siding eliminates that problem but costs more
Most manufactures have 3 product levels
base
midlevel (sometimes called "commercial") which is built to higher specs
top of the line flagship trailers , usually "race" trailers with all the bells and whistles.
IMHO, I would stay away from trailers made in Georgia, they all seem to have a terrible quality reputation. They are priced cheap because they are cheap. I have compared their weight to exactly the same size Indiana trailers (8.5' x 24') and usually find a 3-400 lb. difference. It's not because they use light weight aerospace materials.
aluminum construction vs. steel is a buyer's choice.
Aluminum is lighter allowing more payload but carries a hefty premium