Rubbish.
Could not open the device to insert supplied separate battery but discovered there was no need yet as it is also supplied with inserted battery, (instructions virtually worthless re this). Suspecting therefore that batteries may not last long. Damaged the feeble plastic casing trying to open it. The noise emitted is much too soft for my 73 years old ears. Would have returned it if I'd not damaged it as aforesaid. Good idea badly executed and not worthy of the Audi logo.
Verified purchase: YesCondition: New