dapinky wrote:Having got round to re-fitting the pack, I can confirm that the motor works on all 4 speeds and nothing has melted yet!
I'm assuming that the resistor pack is at its hottest when the motor is running at it's slowest, and thus when the least cooling air is flowing over it. As such, I have been trying to run the car with the fans on their lowest setting to see how it goes - nowt melted yet

Good stuff and you are correct that slow speed is worst case for the smallest resistor. Perhaps as final proof, you could block up some of your screen vents with a towel or similar and provided it survives, I'll go ahead and confirm the design.
The plan is that once the group buy is complete, the fabricator will offer them to any stragglers... There may be some development costs to be amortized into the final prices, but to give you an idea:
If everyone on the list commits to buying, they should come in at about £4 each.
He is selling similar resistors singly at less than £7 incl. P&P to the UK or £8.50 to the US.
He also offers a repair service at £11 in the UK or £13 to the US.
Once Pinky confirms they survive extreme conditions, I would like to send him one to repair (repair cost to be borne by the group buy) so would anyone in the UK care to volunteer a duff one to be repaired? First come, first served so if you're kack-handed with a soldering iron, now's your chance.
I suppose that if anyone would prefer to have them repaired rather than go for the group buy, then it shouldn't be a problem, so long as too many don't drop out.