Electrical issue?

[Duquette5]

Helping a friend diagnose some issues with his new 2001 Boxster. I helped him pick it up over the weekend. He was able to drive it home almost 50 miles with no issues aside from a slipping clutch. Got home and shut it down and now has these symptoms:

no radio
no power to the windows
no start
top doesn't work

I opened his key fob to check the battery and it had no electronics in it, just the pill. He replaced the ignition switch and that didn't cure anything. Battery has a fresh charge on it. Immobilizer was wet so I had him pull it and blow it out and set it in dry rice for a day. Still nothing. What should we check next?

Thanks!
Mike