[paulgato]

I have an android app - Torque - and it works for some things. It shows coolant temperature with perfect accuracy for example, and I use it for that regularly, as VW have included only an idiot guage on the dash which shows a needle pointing dead-centre at what is marked as "90" at any temp between 75 and 107. (Thanks guys!) But it is really bad at measuring fuel used or mpg or anything like that. It is kind of useful for measuring engine load. I think the problem may be that in the UK OBD2 didn't come out for diesel cars until 2004 (?) so mine is not 100% compatible with these toys. That's another reason I haven't shelled out on one.

And yes, I have some Dynamat lying around. It has quite a thick foil layer on the outside so it might be useful for dissipating heat. I also have some thin (1mm or less?) aluminium sheet lying around, which might be better. That stuff is super-easy to work with as it can be cut with scissors, ...or tin snips anyway. Looking today, it seems that one end of the battery box gets quite hot and the other end stays quite cool. The battery probably doesn't like that as one cell will be much hotter than the others. Better to spread the heat evenly around the battery with metal sheet I guess. I think the problem is mainly heat radiating off the engine block.