"I would rather drink tomato juice tonight, as my stomach is a bit upset," Count Vlad explained politely. "However, I'd rather you didn't bring any garlic bread to the potluck. I'm highly allergic!"

When the subject of "would rather" is the same as the person doing the action, we use the bare infinitive ("drink").

When the subject wants someone else to do (or not do) something, we use "would rather + subject + past tense" ("you didn't bring").