I bought this item because it was one of Auto Express magazine's 'best buys' for sound quality.
Presumably they either tested it on a much nicer car than mine (a fairly safe bet) or didn't power it with the in-car charger, because as with other reviewers all I got was this awful howling interference - in-car tinnitus with the faint sound of my music in the background.
Presumably the manufacturers didn't get round to thoroughly investigating this flaw, being far too excited about the utterly pointless thermometer feature.
However, use batteries and it's a different game - a really excellent, clear sound. In fact I hooked mine up to my hi-fi separates system at home which might expose any hiss or flaws in the sound quality and again it gave off a really nice clear sound with a transmitter range of around 15 feet or so.
I really love my Jivo - it's a great buy but I'll be needing a pack of AAA rechargeables to go with it.