I just finished another overnighter in the Ford Escape hybrid. This time I took along an FT-817 and an FT-50 handheld in addition to the FT-2600. I listened to the transmit audio from the FT-817 and the 2600 on the handheld and I couldn't hear any noise on the signal. I tried the FT-817 on both VHF and UHF.
I also listened around on other bands on the 817. Six meter receive was clean, both on FM and SSB. I listened down on HF even though I didn't have an HF antenna. The only thing I noticed down there was a considerable amount of ignition-like noise on 17 and 20 meters -- about S8. But, the noise blanker cleaned it out. I'll probably get the chance to try HF transmit in the next few weeks. In the meantime, if you try the TS-2000, I'd like to know how it comes out.