John from your description if I was the inspector you would fail and have to start over.
part of 411.4
411.4 Locations Not Permitted.
Lighting systems operating at 30 volts or less shall not be installed (1) where concealed or extended through a building wall, unless using a wiring method specified in Chapter 3,....
The wire you are using is not a chapter 3 method.
Also are you using 14 AWG with the 300 watt transformer.
14 AWG requires 15 amp overcurrent protection.
The 300 watt transformer provides 25 amps.
[This message has been edited by iwire (edited 01-05-2004).]