Thanks for the info. I purchased the car last November and it never really had issues going into fifth. It seems to be getting progressively worse, taking longer and longer as the months go by. But you could be onto something with the Winter weather playing a part in the issue so thank you for opening my eyes to that. I will see how it goes as the warmer months come through.
I did see a pic of an NM35 with the R35 front on it and it was hideous! I like the look of R34 though, but I am guessing that it's only the older models that can take the R34 front?
I think the exhaust might be a custom made job....... Have not been able to see anything on it to identify brand. Looks like mandrel bends and extremely tight, clean welds though. Has a twin pipe rear muffler which I will soon be replacing with a big single pipe muffler, as it will look much better I think.
Under bonnet is fairly stock I think. I am going to order a decent air cleaner for it next week but haven't decided as yet which brand to go for. I also want to get a BIG front mount for it and an alloy radiator and better coil packs. As far as I am aware, the previous owner only did exhaust and tranny cooler upgrades.