As others have mentioned, use at least a 5200# axles with brakes on both axles. Over the years I've seen enclosed trailers with 3500# axles that have the tires tilted in at the top. It doesn't cost much more to upgrade to the right axle. IMHO on any 24' trailer it should be mandatory to run at least a 5200# axle. My 18' open goose neck car hauler has 5200# axles under it.

Buy good tires. I tow with a open trailer and last summer installed 15" Goodyear Endurance, load range E radials. It tows nice and smooth, money well spent.

What? Goodyear finally makes a good trailer tire? If you put truck or car tires on a trailer in Illinoise you WILL get pulled over and fined bigly...

It's a trailer tire. I don't live in a communist state, thank God.

I guess the real topic here is transporting a race car. That being said, last week I stopped off at a used school bus lot. Not sure I'm maybe fond over the finished look, and one would need some fabrication skills, but with a diesel real truck air ride chassis, converting it to an RV, and an enclosed car hauler, with always the possibility of hauling a second race car. or an errand vehicle, I liked all the options. School buses appear to be become obsolete (seat belts, crash protection, etc), rather than worn out, are seldom if ever overloaded, likely are run empty 50% of their mileage, are well maintained, never driven hard, are rather plentiful, and come in all sizes. Biggest downside, to me they are seldom high or over powered.

i always liked the idea of using a school bus as a vehicle hauler. around here, the prices i have seen seem cheap to me for a pretty nice, somewhat low mileage starting point.
as i have had the "privilege"[ ] to drive trucks with auxiliary transmissions, the ones where you loop your arm through the steering wheel to shift gears, the "low or under powered" statement might be a moot point with a two speed rear axle.
however, most buses now days are equipped with automatic transmissions, and i don't know if a guy could retrofit a two speed rear axle to one of those or not.

Mack B-61 Thermodyne with a Triplex? A buddy of mine had one he pulled a low boy with, it was always fun watching him double clutch with one arm through the wheel and a shifter in each hand.

those B-Macks were a real Hoot !
shift SIX times to go TWELVE feet !

I adopted my dads 28’ trailer after he retired from racing. Sold my 24’ Haulmark. The 28’ is on leaf springs that definitely have required a bit more attention than the torsion flex my old trailer had. There again it went a good 7 years and had multiple trips from SoDak to AZ on it and I used in two of those putting a lot of miles on it too. Shackles and bushings wear out and we had an axle replaced to rid of some weird tire wear issues. I’ve also had a friend that had the rubber on his torsion flex axles wear out and it was a costly procedure to replace them. Disclaimer is that living in the hot/dry desert is hard on rubber anything... most will never have issues. Don’t buy a box trailer with 3500lb axles PERIOD! 5 and 7k axles usually have the EZ lube set up too for the wheel bearings. I do have the 16” wheels and my latest experiment in trailer tire he77 is running G rated 14 ply tires. Longest I’ve ever gotten on a set of trailer tires is 3 years.... again, life in the desert. Not uncommon to pull over and hit the tires with the temp gun and see 160 degrees.