Start by placing your fixed items, then locating the others where you want them then just runt eh wires ina way that makes sence to you. I placed the MS ecu inisde the glovebox and the relay box on the battery tray along with the msd box, I ran the injector, distributor wiring straight back tot he firewall then over to the battery tray area. In the 280 it might be a better optiont o locate the ecu and relay board in place of the stock ecu and run the wires to the firewall then over the master cylinder and through the stock hole int he firewall. I did also drill a hole in the inner finder beside the clutch master so I coukld run wires to the coil in the stock location. Just take your time and run one thing at a time, leave a little slack int he wiring, and once it's all run start bunchign up allt he stuff that runs along the same path.