my dealer has today fitted a replacement bolero unit and i have now lost the on screen text mode for my phone and i think the media sd card reading is slower, have they fitted an older unit? and if so is there any way i can tell?

I'm not sure how to check the version number but slow sd card reading is a sure sign of old firmware.

Go back and shout at them!

Not sure what 'screen text mode' is - do you have factory Bluetooth installed? But slow SD reading is your sign I think. Don't know if there's a way of reading firmware version from the unit itself - not spotted it myself. The physical unit will just display the part number, as will VCDS. A diagnostic scan might bring up some firmware info, if you have VCDS or know someone that has. I'll check some of my logs files and see if it lists Bolero firmware version there.