I have a TL magna. It has a thick layer of tar based SD under the back seat from the factory (not sure if this is the same with all models).

I have had power cables and RCA's running over this stuff for about 2 months. I am currently upgrading the amp and i just had a look under the seat. Where the cables have touched the tar it seems to have melted.

I wouldnt have been so surprised if it were just the power cables (even though I have 4AWG running a 2x80WRMS amp, so it shouldnt get hot) but event the RCA and speaker cables are the same.

I am pretty sure there is no reason for these cables to get particularly hot, everything has been working perfectly, and i am pretty carful with all this stuff.

I am guessing it is just really poor SD, but i just wanted to know if anyone else had experienced the same problem.

are the cables being squashed at all? this tar stuff is very easy to squash when it is warm and i'm sure mine have also made a nice little recess where the cables are

are the cables being squashed at all? this tar stuff is very easy to squash when it is warm and i'm sure mine have also made a nice little recess where the cables are
Yeh that's what i was thinking, the power cables do get abit warm, but i've noticed that tar stuff in my TR is very squishy.

I have the same problem in my car but only where there is pressure on the cables.

Yeah I think thats it. I have just placed all the cables so they dont touch the stuff.

It was pretty messy though, that tar crap was all over the cables.

yeah, i wouldn't say its all the cable's heat thats causing the tar stuff to be sticky and soft. Your car body heats up quite a lot, after u go for a drive, or leave it in the sun or whatever. The cables apply pretssure, and cause an imprint. Things like RCA cables don't really heat up at all.

With the heatwave we had a couple of weeks ago i'm sure any sound deadener would of been softened. I too highly doubt the cables were the cause.