I have used a Pontiac Grand Prix, Toyota Solara, and a Toyota RAV4 to tow small camping trailers. The 2015 Toyota RAV4 is the only one capable of towing 3400 #. I bought it used. It came with factory tow package and AWD.
I think the factory tow package is a better solution for a small tow vehicle. Cars are carefully designed and tested for a specific set of uses. You need the specifications for the specific make, model, and year. Hopefully the drivers door frame stickers will contain the maximum specifications allowed for the vehicle you are considering. Otherwise consult a dealer who sells the brand you are considering.
You may have a lot more to learn if you are going to modify a car to tow a camper or travel trailer. It is not a simple subject. My experience with an add on hitch for the Grand Prix was poor. The body flexed and bent while towing a 900 # flat bed utility trailer. The paint on the after market hitch peeled off in large sheets in 3 years.
The Solara worked better using a Toyota dealer supplied hitch. I towed a 1500 # MGVW folding trailer against a 2000 # max towing capacity spec. I had to add a brake controller for electric brakes and 12 volt line to keep trailer battery charged for brakes. High speed tires wear out fast while towing. Transmission oil had to be changed much more often.
The RAV4 worked best. It was designed for towing and had towing capacity significantly higher than what I was towing. I still had to add a brake controller and 12 volt power line. Towing with it was much less stressful. I didn't have to constantly think about driving too fast or maintaining a long stopping distance.
200 # tongue weight means you cannot tow more than 2000 pounds. Tongue weight must be at least 10% of trailer weight for safe towing. 15% is more stable.
An SUV (not a crossover or other pretend SUV) is usually required for towing 3500 #. The 2015 RAV4 was built on a frame. Later models were uni-body and did not have the same towing ability. In later years Toyota may have marketed a beefier RAV4 model.
You usually cannot tow safely at the maximum rated towing weight. No, not just my opinion. The maximum, is indeed the maximum, but other things reduce the maximum.
The weight of everything added to the tow vehicle after it left the factory decreases the maximum towing capacity. There is a 150 # allowance for the driver. Absolutely everything else added counts. All passengers, luggage, equipment, trailer hitch, etc. count.
Cargo capacity usually limits. The MGVW (Maximum Gross Vehicle Weight) from the driver's door sticker minus the Unloaded Vehicle Weight gives Cargo Capacity. Subtract weight of everything added including trailer hitch. What remains is available for tongue weight.
Tongue weight must be at least 10% of trailer MGVW (from sticker on front driver's side of trailer). Actual weight is what matters, but most travel trailers are towed at or near MGVW. I would guess you will not have more than 200 # available for tongue weight while towing with the Subaru.
Pushing the limits of a tow vehicle requires you do the math. Follow up with a trip to a commercial truck scale with your fully loaded rig after you buy it. Get actual axle weights for $15 and check against tow vehicle specifications.
I wish you good luck and happy trails ahead!