Is the ipod suitable for the headunit?
I mean, does it say in the headunit's manual it can be used in conjuction with said ipod touch?
yes but ipod touches are different from other ipods due to their programming. It may be that your grande punto (or the radio) was released before the ipod touch came out. Most after market head units come with a list of ipods they are compatible with, so it may be best to go shopping for a new one?
http://www.ipodsaccessories.info/ip...touch-2g-3g-ipod-nano-4g-iphone-3g-black.html
Something like this should work, ive never tried it though. Ill get in contact at some point and make a list of what does what.