I asked the question of autoelecau - will the warranty be honoured if used under the bonnet? and received this response
"Yes , as long as if it should fail it is NOT because of heat."
Which is a bit lame. So it isn't really suitable under the bonnet at all. Saying "Suitable for any location including under bonnet use" is deceptive if the warranty doesn't cover normal (ie. hot) conditions under the bonnet.