Connected up the GROM using the RVR cable and nothing blew up!
The good news: The iPod plays through left and right channels with amazingly good quality and full control is available from the iPod. The volume controls on the steering wheel work as does the mode switch to swap between radio, tape and GROM. CD button on the Alpine HU also calls up the GROM with CD1-01 displayed on the HU screen.
So far, so good.
The bad news (or not so good news): Pressing the CD selection buttons on the HU calls up CD2-01, CD3-01 etc. as expected but the GROM does go into ‘advanced’ mode and does not select the playlists as advertised in the instructions. The GROM remains in simple mode. Using the seek buttons either on the HU or the steering wheel does not skip to the next/previous track in manual or fast forward through the track in seek (non manual) mode as stated in the instructions. These buttons work OK for the radio and CD player so it’s not a problem with the HU or steering wheel controls.
Not a total disaster by any means as all controls are available from the iPod but a bit disappointing nonetheless.