sp1ke

Hi We're looking to buy a 59 plate Rx450h & just making some enquiries about how the satnav maps can be updated. I've looked at http://www.lexus-mapupdates.eu/ but they don't seem to offer anything for the RX450. From a few initial inquiries it seems the navigation is now hard drive based & new maps are released every November. The Lexus service/parts department have quoted around £250inc vat to update the maps each year which includes 30 min's labour at £60+vat. This seems extortionately expensive, so I was wondering if it is possible to get the updates from another source eg direct from navteq or whoever the supplier is? & if its possible to DIY the update to avoid the labour charges. thanks in advance S.