I know this subject has been covered a number of times, but I am not sure I have ever seen somebody positively say they have resovled the issue and could really do with the forums input. Essentially my R500 like all R500's gets incredibly hot in the cabin, and after a fairly unbaearbily 2 hrs drive back from Bedford last month in 30degree sunshine I have finally decided to take action. Reading through the achieves there seems to be 3 main forms of prevention which I will list out below. Really interested to here peoples experiences of these and whether they have managed to cure the problem specifically on a R500D 1. Heat insulate the tunnel and footwall ends. I will 100% do this, but am told you can only really access the foot well ends without removing the engine, so will buy the kit from Caterham now, fit the ends and the wait for the next clutch change or similar to line the inside of the tunnel http://caterhamparts.co.uk/product.php?id_product=4247 2, Carpet the inside. Im pretty sure this will just delay the heat soak rather than cure it but if it will probably mean I can rest my leg against the side and hopefully even drive in shorts without worry about scotching myself it's worthwhile. I did also see that thundersport have some very nice carbon effect side panels which is insulated on the inside. Has anybody got an ecperience of these? Do they help at all and how do they look fitted? http://www.thundersport.co.uk/index.php/lightweight/caterham-7-series-3-transmission-tunnel-heat-insulation-both-sides-carbon-vinyl.html 3. Ceramic Coat the exhaust manifold with Zircotec. I am pretty sure this is the most effective way of stopping the problem but it does come at a cost both finacially and time off the road. Believe it comes in at around £500. I plan on doing this over the winter months while the car is laid up.