Can RCA leads be shortened?

yeah, but i wouldnt suggest it.....and if your gonna join, join em in the middle-ish and rewrap them.....but ultimately id suggest not to cut them unless 100% necessary

They are around 2m to long & I want to get them cut to length & a new end fitted by a Car Audio specialist. (not by me)

Just wind the extra under the carpet. You are better off not cutting them.

Yeah ul easily ruin a good set of rca's as they are hard to get right (beleive me I've tried) :(

just use cable ties and tuck them away some where. thats what i did.i purchase bout 6 metres only used about 5.5

mmm, you could go out and buy some RCA connectors, silver wire, teflon sleeves, etc etc and try and make your own RCA cables...but yah, RCA cables aren't that easy to make.