Montana 700i carholder very low volume

Have the 700i in use for couple of weeks now, great unit. Received the car holder (windscreen suction cup type) yesterday.

Hip hip hurray for:

- Upgrading to RAM mount ball (1 inch)

- Power supply by micro-USB, so now you can use every USB powersource (lighter adapter/powerbank) for powersupply to the unit.

Negatively surprised by the very, very low volume of the speaker.....in a normal car with roof & windows closed it's propably understandable. In my Lotus 7 (has no roof or windows...) you don't hear ANYTHING AT ALL!!! Unless you're doing 20mi/h or so the speakersound drowns in it's surroundings.

What to do about this? Tried several voices in US & British English as well as French, Dutch and German (i'm from Europe and speak&understand 6 languages fluently). Neither of the tried voices gives a better result. The sound is good quality but the volume is way, way, way too low.

Please Garmin, get us a solution for this....