I only had a valet key and FOB for my 2004 civic. It went missing at work yesterday and was found in another part of the building. How worried should I be? What precautions should I take against a break in or car theft? I already had a Honda stolen once before and have lost two nights of sleep over this.
I lock the steering wheel and use a club, what else can I do.

 

Your key has a computer chip in it. To make a new key you would first have to get a copy made, which is not easy as going to Walmart with the sidewinder style keys (which you have). Then, you would need to take it to the dealer and have them perform the learn procedure so the computer would recognize the new key. Some high-end locksmiths may be able to do this, but either way they would need access to your car, can't just take the key somewhere and have a copy made. You can have a key cut that would just unlock the doors, but I have yet to find a location other than the dealer that will cut a sidewinder key.

I wouldn't be concerned.

 

Actually it is possible for someone who is skilled to now steal your car unfortunately. It is unlikely that someone has the knowledge or the parts to do it. Using your key they can program an interface module (the same thing that is used in a remote start). Using the interface and a blank key (that would function for the door locks) to let the steering wheel turn, the vehicle could be stolen. Installing one of these interfaces takes knowledge of the vehicle that you are installing it on, knowledge of the interface and time alone with the vehicle. So the possibility of the car being stolen is there but very unlikely.