Newbie questions: Tiny toy haulers

It's been a while since I posted this question. I've come up with another idea that's probably been around. ? I'm thinking of getting a 5x10 open utility trailer then building modular boxes for a kitchen, bathroom, and sleeping/storage. For 10 feet clear length, maybe a 6 foot sleep/store box, a 30 inch bath/shower box, and an 18 inch kitchen box.
They would each be 5 feet wide and have windows on the sides but the front & rear side would have matching window-door panels that could come out so adjacent modules would seal together with a large pass-thru opening.
The trailer with plates could always be stored outside while unused modules couldbe built low enough to fit in my garage when not in use. The module height minus axle & flatbed would be higher than a full trailer that would normally fit in the garage.
Each module would be self contained for fresh & waste water storage.
Starting with a 2000 pound trailer with an optimistic 1050 pound empty weight, the 3 modules would have to be less than 950 pounds total in useful shape. Then based on needs of the day or weekend, leave a module or 2 or 3 in the garage to gain useful hauling weight.
What do you think?
I just wanted to add that I am not committed to a DIY project, so if you know somebody who sells something similar I'm all ears. I could also change tow vehicles without much of a penalty, but I am thinking that every commitment to one thing is also a barrier to other things (like trying to keep my jeep limits my options, perfect example). I'd really like to have a utility trailer, and a half-toy hauler, and a small camper, and a picnic kitchen, and so on. It's not a thing for the full-time RV life but for the suburbanite it might work out well.

Tour1 wrote:
...My Jeep does not have a factory tow package...

I found a similar Jeep for sale, plugged the VIN into the Jeep website and got the equipment list. These are line-for-line identical, even colors and spec dates but the "Trailer Sway Control" is definitely there and you can't fight city hall. Mine has a compact spare tire listed that's not on the Tow Package car. Meanwhile these items are "factory" on the Tow Package Jeep:

Trailer Tow Class III Group
Trailer Tow Group
Trailer Sway Control
Power Steering Cooler* (*service docs say both have this)
Engine Block Heater
Heavy Duty Engine Cooling
Full Size Spare Tire
Black Steel Spare Wheel
Class III Receiver Hitch
7 Pin Wiring Harness
7 to 4 Pin Wiring Adaptor
Schedule D To C Tracking
D1-To-D Regress
Distribution Services Tracking (**2nd time, mine has this only once)

Macs Dad wrote:
A bear proof toy hauler?

Yes- mine has the Sig Sauer P229 option.

Case closed, right or wrong, and this is why I didn't really want to ask a dealer anyway. My parts guy said (give or take a few words) "Mopar does not have an upgrade kit to add the factory tow package" but I should be able to find it aftermarket "because they'll make anything" but what really cuts the cheese here is when he added "an aftermarket tow package will void your drivetrain warranty". So without learning a single thing about the tow package parts I have the negative no way can't be done conclusion.
So I will be looking for another vehicle, changing plans, whatever, but I leave this little note, a hitch available for a mini-cooper is rated the same as the alleged limit on my 2-ton Jeep. Of course, you probably need the rare and expensive mini cooper factory tow package...

I went to the dealer before work but they were too busy and I ran out of time.
My Jeep does not have a factory tow package.
I will be asking if I can retrofit all the equipment.
Meanwhile, I now know that U-Haul installed a Class III hitch without any hint that the as-installed limit was 2000 pounds. Somebody knew something (I think) because they put in the 4 pin connector, although I did need 4-pin functionality for my 1000 pound bike trailer, I'm not sure I asked for it to be just 4-pins and I'm not sure I didn't.
The Jeep service manual covers hitch installation and removal including the 7 pin connector "if equipped" but I haven't located any reference to an electronic anti-sway control of the type infamous on Wranglers. It needs further inquiry.
A post I found on another (I think) RV forum is from a Liberty owner with tow package and they imply that a hitch sway damper is required in addition to the load leveler/equalizer.
I have a question about brakes: I recall seeing piston-actuated hydraulic brakes on trailers years ago. When the trailer started pushing the ball, the piston applied brakes on the trailer. Are they still used? Something special needs to be done to back up but I thought they were ok when I saw them.
If electric brakes are required, do they have to oscillate along with the ABS brakes on the Jeep? Do (or can) they use an inertial control like the on-dashboard model I saw somewhere?

Tour1 wrote:
Just an update. I have the service manual now, checking for relevant data.
I don't have the tow package but I found one like mine that does, for sale in MA and asking more now than I paid then. The hitch is nearly identical to my U-Haul. The dash & console are identical. The hitch doesn't have a setup for a damper on the hitch, maybe that would go on the ball area when installed and not be part of the factory package.
Rumor has it there is an Anti-sway engine control that some Wrangler owners would like to remove or disable from their Wranglers. Posts indicate it can't be installed or removed in the field but I haven't found it in the manual yet. I suspect this is another robo-nanny that prevents idiocy but bothers people who know how to drive.

Knowing how to drive and having the right tools for the job are two very different things.

Just an update. I have the service manual now, checking for relevant data.
I don't have the tow package but I found one like mine that does, for sale in MA and asking more now than I paid then. The hitch is nearly identical to my U-Haul. The dash & console are identical. The hitch doesn't have a setup for a damper on the hitch, maybe that would go on the ball area when installed and not be part of the factory package.
Rumor has it there is an Anti-sway engine control that some Wrangler owners would like to remove or disable from their Wranglers. Posts indicate it can't be installed or removed in the field but I haven't found it in the manual yet. I suspect this is another robo-nanny that prevents idiocy but bothers people who know how to drive.

Tour1 wrote:
Years ago I had a boat, Bearcat outboard & trailer that I towed with a Mustang II. .

AH, pretty much the original 4 stroke outboard motor. on the Mississippi river they would "anchor" them by pulling up to an island going upstream and just letting it idle in gear holding its position.
quite an engine.
bumpy

get a 6 X 12 single axle with an rv door on the side and convert it the way you want. Make sure the trailer has brakes.

Yep, build/convert your own as mentioned above.

We did because nothing new on the market fit our specific needs and budget. My 7x16 tandem cargo had a curb weight of 1,990 lbs. You could easily get a smaller unit to better suit your tow vehicle and haul your motorcycle, etc.

7x16 cargo conversion

watermarks...arrgh, but you get the idea.