2006 convertible, loaned to a friend, he left the radio on, he tried to jump start it and he said he crossed pos & neg for about 5-8 seconds and then lost the key. yesterday put in a new battery had a new key coded to the vehicle and it will not even turn over top does not work no horn, no radio,but the odometer and oil light come on, checked fuses, all good? any ideas?

 

With friends like that, who needs enemies? If he fried the engine computer, it's going to be a big bill. May have fried the radio, too. Get a code reader and retrieve the fault codes in the computer. Go from there. And never loan your car to this guy again.

 

There are also fuses under the hood. I would check the starter fuse.