Just like you, I decided the winch was a good investment in a happy marriage. Much, much cheaper than the divorce that would have resulted from attempts to drive the car on the trailer!

Check the boating supply places. I bought a cheapo manual (no electric) winch rated at 4000 lbs. rolling to pull the Miata onto my open trailer for around $70 with a 35 foot cable. I can bring the car up on the trailer in about two minutes with no problems at all. It's bolted in place with two grade 8 bolts and gets stored inside during the winters, but otherwise has done well exposed to the elements over the last four years or so.