Is my Medion Sat Nav upgradeable?

[elanfan]

I bought a Medion Go Pal PNA315 largely 'cos it was on offer in Sainsburys £49.99 down to £29.99. I've read that this was a little used model originally developed for the Oz market.

Used it this weekend and even tho' it has fastest, shortest and Economic route options I could see it was taking me around the houses to get to my detination. I literally ignored it a few times and it recalculated the route to what would have been the best route in the first place. Near home it tells me to turn right where there is no right turn! On the weekend i was staying at a Hotel in the Services off the A50 near Donington if anyone knows it and it totally ignores the dual carrraigeway that is the A50 and has me going up little b roads to try and find this Hotel

Long and short is I am not happy with it - I can take it back for a full refund but before I do can anyone tell me whether I can delete it's 'operating system' and mapping and upload say a Tom Tom version on to it instead. If I can then £30 quid would not be so bad.

If anyone can point me in the direction of an idiots guide to. ... it would be great

[elanfan]

I know there is an awful lot of knowledge in Pistonheadsland could someone please spare sometime to share it please.

I'd be grateful

Cheers