A brake buddy is not really needed for the smart, but IF you're determined to use one, I would suggest you wire a new outlet directly to the battery. I used a 10 amp fuse on mineI have been using my 2009 Cabrio for a toad and would like to use a brake buddy. My accessory plug is dead when the key is off. Can I wire it to be hot all the time? Where do I reattach the wires to make this happen?