Serroots

Hello all,
I am going to install a Nexus 7 tablet in my 2002 A4. Right now i have a radio removal key stuck in one side because for some reason on the other side (this is a concert radio btw with the very modern tape player) the key just freely slides in and out after clicking it in once and it pulling out without taking the radio with it.

Anyway, I will be installing a cheap single din head unit where the CD changer currently sits, but want to make sure that if i pull the power from behind the stock radio (i will remove the centre console and possibly glove box to get it out) i can plug into this harness: and into the new head unit without any radio code problems. As far as i know the radio codes are to protect the radios themselves from theft so they can't be used in another car, but i want to ensure before i do anything that i can plug that power cable thingy into the new head unit without any problems.

Obviously my knowledge is rather limited regarding car audio but i'm slowly learning.

Will that harness be enough to wire speakers and all into a new head unit (i will go AUX from the head unit to the Nexus because it seems to be the easiest way)? I just want something cheap like this: http://www.jbhifi.com.au/car-sound-g...it-sku-366520/

Thanks!