Reception problems with stock stereo + new headunit thoughts

[andy_mac]

As above, I've got an extremely annoying crackle from the stereo.
Never does it when stationary, only when moving

Have pulled the headunit out and redone all the cable joins behind it I could see. Did find one sus as join that was just twisted with a little bit of tape holding it all together but didn't make things any better even with it done properly.
Made sure aerial cable is tightly mounted and no visible damage from kinks, also tried running the system with the band expander removed which made zero difference aswell.

So I've run out of ideas short of somehow jimmying up some kind of temp aerial to see if that crackles too. Doubt it would be a fault in the headunit but have no way of checking that option until I can decide on a replacement.
Any ideas on what else could be checked??

On a side note looking at some double din replacement head units, does anyone have any experience with kenwood?
From what I've been reading they are getting right up there with the other top brands these days and not just cheap crap. Still leaning towards alpine though considering their successful older units.

Loosely tossing up between these two

http://www.qualitycaraudio.co.nz/ind...ice&order=DESC

http://www.qualitycaraudio.co.nz/ind...ice&order=DES