Bob,
You should be able to tow up to 4500 lb trailer/auto combination without issue with your Sprinter. Here are some examples:
Trailer:
https://www.rondotrailer.com/invento...ler-50fb-60184
Trailer cost $1,940.00 cargo capacity 3400 lb. Trailer weight 1600 lb. To stay under the suggested towing limit on your Sprinter in this case you would need a car weighing 2900 lb or less. Trailer 1600 lb plus car 2900 lb equals 4500 lb which is about 200 ld under your limit. Now this example is with a low cost 16' steel car hauler trailer. The weight numbers get much better with an aluminum trailer but the prices rise to the $5,000-$7,000 range. Still with this type of low cost trailer you could haul any of the following cars.
Toyota Matrix 2888 lbs
Honda Civic Coupe 2617 lbs
Mini Cooper 2535 lbs
Hyundai Accent 2396 lbs
Hyundai Elantra 2701 lbs
Nissan Cube 2768 lbs
Nissan Versa 2354 lbs
Ford Focus 2955 lbs remember I gave you 2900 car limit but it is 200lbs under the max weight.
If you want to tow a slightly bigger/heavier car go to the aluminum trailers.
If it's not about money, go with an aluminum tilt trailer. I have one and love it.