AH! The penny has dropped. Thanks Giomen. Yes i knew that the vehicle charger cable was used as an antenna for on-board traffic receivers [much as a mobile phone earpiece cable is used as an aerial for radio reception], but didn't make that connection until now [Bl**dy translations!]. So, is that 'version' of 2497 only available in RU region or are there other on-board regional versions in EU as well?

Also, can you add a JM sub the same as with an external GTMxx?

PS: I've bought bits and pieces from Russia. 2nd hand screens, GTM21 recently [it had a US 3 month sub on-board strangely], but never a new unit. One of the few types of units i don't own is an on-board traffic model [someone was going to go to Germany last year to buy me a nuvi 150 for Christmas but spent the money on Vodka instead i think ].
Best you send me one of those Ruskki 2497s this year or i'll sic my 'roo onto your bear's sorry saggy brown a*se!