Here's the deal on what a repo title is. A repo title is the paperwork from the lender that declares that the car was repossessed. Ideally, the dealership that sells the car should flip the title into their own name. Otherwise they are attempting to skip title, which NJ hates because that's a lost sales tax opportunity. The reason some leasing companies do not get the final title is because of the paperwork and time. Time is money and some states require a lot of paperwork for repossessed cars. Remember some leasing companies are dealing with 100's of cars. They would prefer to deal with the minimum of paperwork and waiting time as possible. Licensed car dealers in NJ should be able to get the title transferred to their own name with basic repo papers. Part of the repo pack is when, where and for how much the repossessed car was sold for from the leasing company. If the seller is not the repossessing company, they can't simply transfer the rights to the repo pack over to you. They have to go through the proper process and get the title. And the process can take weeks if it's an out of state title.
In NJ, a sale is only valid if the legal ownership papers (title) are properly transferred to the seller of the car before the sale. Somebody saying he's selling the car on behalf of his buddy who's the actual owner will not be able to sell you the car. Ever. No exceptions. With an out of state title, it must be properly transferred per the rules of the state it is issued in. And again, the person listed on the title must match the person who sells the car.
My advice to anyone who is buying a car with an odd title situation: Bring the seller and the paperwork with you to DMV, do the transaction at DMV after verification that the paperwork is complete and acceptable. I lost $1000 on a car because I did not do that, and the seller skipped town. If the seller won't go to DMV with you, WALK AWAY. Even if you really want the car. You can easily end up losing your money, and being completely unable to legally get a title or registration. In other words you won't get the car.
As far as flood or salvage titles, they should have a permanent brand on the title. But they can be laundered through other states. Also, remember that a rebuilt or project car is a salvage car. It doesn't matter if the car was restored to factory, or better than factory conditions, it's still salvage. So you can get a good car that happens to be branded as salvage. Best to know what you're looking at, it's not for amateurs. You can also check to see if it was sold at an insurance auction, those cars do not always have branded titles. Another thing to remember is sometimes the owner of the car will damage it for spite. I saw one Corvette that the owner left on the train tracks because he knew it would be repossessed. Smashing the panels and windows, fouling up the engine, pulling wires, there's some nightmares out there. Again, you can sometimes get a good deal: A quality, well maintained vehicle. People just get some bad luck at times and can't afford the car anymore. They accept it and move on, some people are nasty about it as if all their problems are the fault of the repo man.
Caveat Emptor.