My battery went flat again yesterday, which is probably the fourth time in the past couple of years. I have the following electrical issues:

- Constant drain of about 0.75 amps when the car is off and locked.
- Reverse parking sensors only activate intermittently.

Does anyone know what the normal drain of a 2004 2.0 TDI DSG Sport should be? Is there an easy way of diagnosing what the cause is? Does anyone know of any reasonably priced people in West London/M4 corridor who might be able to take a look at my car and fix it?