Is the smaller camera 5Q0 or 3Q0? If yes, it's platform so most likely that you won't get that to work as it would require other bits and pieces as well.
3AA camera should work but sign assist will be difficult, some say it works, some haven't gotten it to work. What I've read about this it seems it's a software match or mismatch. So with some camera + RNS510 SW combos it works but some don't.
Also high beam assist no. I heard there's a separate module for the 3AA camera that allows LA/ (light assist / fernlichtassistent) functionality.
3AA 980 654 D camera supports light assist, if car other modules support it (for example ).
Sign assist works in west europe. In east europe countries, it does not work when there is east europe navigation data installed into RNS (it kind of works with west europe navigation data in east europe - it reads only visible speed signs).
Also 3Q0 980 654 camera works. I have this camera in my B7 passat and Sign assist/Lane assist and DLA/ works. But as this camera is smaller, adapters are used (with adapters, they can be fitted to original 3AA camera holder with little bit modification). With 3Q0 980 654 Sign assist works, but not 100% if you have RNS315/RNS510 installed (reads only speed signs), as this camera cannot get navigation information from these headunits. If you want 100% sign assist working, then you need discovery media (then you have full navigation support to sign assist and it can get speed info from map if no visible signs present)
3Q0 980 653 cameras should work only with .
5q0 cameras are very different shape and i think it's impossible to fit this camera.
(sorri if I missed some information... did not have time to go through all the thread
)