This is how I read it: "I wish my car never broke down" This is referring to an on-going state of your car. For example, one might say: "I wish my car never broke down, but it does all the time." I think these are both present tense. To refer to a specific event in the past (of the car breaking down), you would say: "I wish my car had never broken down." OR "I wish my car had not broken down." OR "I wished (past tense) my car had never broken down"

It's not really a tense. "Broke" is in past subjunctive form, so we understand it as the unreal present.

Could someone give me a clue?