I have a new head unit & speakers installed in my TS and it sounds great. The problem is some times the radio receiption is really bad. I know that there will be some interference with power lines etc that will cause this or is it just because the aerial is rubbish. Is there some sort of plug in ( fix it all up ) that I can buy, or is it grin and bear it? I have noted that it only happens in a few places each day I go to and from work. As you would be aware the aerial is drv/side roof. Thanks...

Powerlines won't really affect FM. Did the issue occur with the old head unit? It's probably the aerial. The previous headunit's tuner might be better too with weak signals, but most decent headunits also have decent tuners (Pioneer etc).

I've had these issues before. I've had stock head units pick up great reception, install an aftermarket and then can't pick up anything. I think its down to the head unit more than anything. I noticed the biggest drop in quality when I put a cheapish (in the scheme of things) Kenwood in my old Mirage. there were complete deadspots where I had perfect reception with the stock one.