By early I think you mean ones from about 2007 when the speedo area was changed to a digital one. Our 2003 1.4 petrol C3 had the temp and fuel gauges which were 6 yellow bars that lit up as the temp or fuel tank level went up. Handbooks from 2007 for the C3 can be seen on the service.citroen site and in the 2007 one it shows the newer digital display with only a high temp warning light. In the 2009 on new C3 there is a blue warning light that goes out when the temp gets to about 50°C plus another high temp warning light. Our 2011 C4 only has a high temp warning light.