It surprises me that many cars (even modern) don't alert the driver in severe event, apart from a small lamp on the dash. This could easily be missed until too late. On the weekend my engine reported low oil pressure, and I just happened to be looking at the pressure gauge as it dropped from 4kg/cm2 to almost zero. Thankfully an independent test showed the engine was actually producing the correct oil pressure.

Since this low oil pressure scare on the weekend, I started drawing up a cheap audible alarm for severe events, like low oil pressure. It could easily be expanded to include any other of the dash lamps, and eventually engine temp. I've been a bit busy lately, but I hope to post up the designs soon...