ALL x20 and x30 devices have the JukeBox/ mp3 player option and FM Tx, from the x40 range ONLY the 940 offers mp3 player/ Jukebox and FM Tx.
Someone mentioned the Bluetooth Remote control, this works with all the x20/ x30 and x40 devices BUT with the 920 and 930 it was supplied in the box with the device. With the 940 you have to purchase the remote control as it isn't included in the box.
For those that want to use an iPOD with the x20/ x30 range you simply connect the relevent accessory cable to the built in socket on the device. With the x40 range you need to purchase the iPOD cable AND one of the accessory mounts, as the one supplied with the x40 only has a power socket that can also be used for RDS-TMC if you have the mini USB style RDS-TMC device.
As for EPT only the 920, 930 and 940 have this feature, this is hardware related and cannot be retro fitted to any other lessor models as the hardware (gyro type force sensor) simply isn't present.
I find the decision to not include the FM Tx or the mp3 player a strange decision for the 540/ 740 models as this was a big selling point for some of the other model ranges. The lack of a BT Remote in the box is a cost cutting measure that I can understand, if a user were upgrading from an earlier model and already has the remote then why do they need a second?
As for the accessory dock, this is a niggle, having to spend a further ?30 to connect the device up to the car unless you have the luxury of a compatible car Bluetooth system that offers both handsfree and A2DP protocols.
Live services are very good, but I am not too sure the 740 hits that sweet spot as a navigation device with in car entertainment capability, an x20/ x30 unit can offer greater flexibility for in car use and is devoid of subscription charges for traffic via RDS (please remember I am UK based), If the 540/ 740 had the Jukebox enabled then I think they would probably sell more, having to purchase the 940 for the basic capability you had with a 520 just doesn't make marketing sense to me, even with the Jukebox enabled the 540/ 740 is still missing the FM Tx hardware - Mike