Like many used volvos, when I bought mine it came with only one key which was the valet key. The valet key only opens the door and starts the car, it won't lock or unlock the glove box, trunk, or storage hatch in wagon models. One option would be to order a replacement "normal" key from a dealer, but my local volvo dealer won't have anything to do with keys. Instead I replaced it with my own locking mechanism for cheap. I did this on my 940 wagon, but it most likely applies to 740s and maybe 240s as well. Construction was very simple. First, I removed the original locking mechanism leaving just a hole in the wood. Next I removed the metal piece the lock engages with which is held in with two torx (t25) screws. Then I took a piece of steel flat stock about an inch or and inch and a half wide and 1/8" thick (thicker would work) and drilled two holes to match the piece I removed. Finally, I drilled a 3/8" or so hole at the other end for the padlock and used a mini-sledge and vise to add a slight bend to it so it would fit through the hole. I used the original torx screws with a little threadlocker to attach it. You can use any kind of lock, but I used a hockey puck lock I got off ebay for maximum security.