Do I have a winnable small claims case if a coworker in assigned parking damaged my vehicle?

Have you filed a claim with your insurance company? You can certainly sue him; but winning may be difficult. You have to show that he acted...

He is a scammer. Ignore him, block him, and monitor your credit for identity theft. You've been scammed.

How to set up an installment plan post-judgment to collect?

Yes, draft it up and sign it. No need to let the court know. Pull up the statutes on interest calculations; I recommend putting it in a spreadsheet.

What can i do?

You need to locate a Wisconsin consumer lawyer and talk with them. It's hard to say what your rights are (or claims against this company) based on...

What can i do if i had belongings in a friends car that had gotten repossessed by her ex boyfriend

Find out the name of the repossession company, and call them to schedule a time to get your stuff back.

My recommendation is to dispute the transactions with your bank/credit card company as fraudulent.

How do I go about repossessing a car I sold in Wisconsin?

File an action for a "replevin" in small claims court.

In Wisconsin--Am I able to sue in small claims court without an attorney?

Yes, you are able to sue. Go to the Clerk of Courts and file a small claims suit.

Are you trying to vacate the judgment, or do you have a judgment against someone? What would be the basis for vacating the judgment?

Yes, there is a statute of limitations in Wisconsin. If it's been 6 years since the loan went into default (or you stopped paying), then generally...