We had one on a gov vehicle. I think it was 5000w. It had a monster alternator thingy that probably weighed 100lbs and then had a big box maybe 2ft long that you plugged into.
As I recall, there was a switch on the console that would turn on the generator and rev the engine up to around 1200rpm. It was pretty cool but cost a fortune.
We had it on a Ford Expedition. By the time we added the Auragen and a custom interior and a crap ton of radios, we had almost $150,000 in that beast:oops: