Insurance was due for renewal on the 25th August and 3 yr warranty expires on the 25th September so ideal time for me to enquire about insurance and fit device if I wanted it. Present insurer, Tesco, wanted an extra £60 on my premium AND would shove the excess to £500 instead of the present £200. I shopped around and got the the same cover as I have now (i.e. with £200 excess) for the same as Tesco was going to charge me without the modification. This was through Autotrader. They are aware of the modification and are OK with it. So I fitted the Synergy. QED