presets??? who uses radio anymore????
though i do hate resetting the clock everytime
if you have the disconnect to keep the battery from going dead for long term storage, any bypass will kill the battery over time
if the disconnect is for theft/security reasons... read on
with the disconnect on the ground cable a fused ground bypass will work, but you will get tired of changing fuses when you turn the key, forgetting to turn on the disconnect
install the disconnect in the positive cable and run a fused bypass to constant on wire to the battery
my 58 truk has an alarm system on it, i use no disconnect but have to put a battery tender on if i don't drive the truck every 7 days