I am long fan of Tamiya. especially the TRF Kits
I would love to see more kits in the shops but the problem for hobby co is simply the cost to buy.
The tax they have to pay and the strenght of the pound versus the Yen and the Dollar means the cars are very very expensive, they cant make any profit as the UK customers would rather buy from hong kong on the cheap then pay the real price from a UK shop.
Its a shame but unless you the punters are prepared to stop buying from far east and support your local dealer the hobby co cant possibly have a reason to stock them.
Its just the world economy works against importing certain goods from certain territories. and also the fact that uk customers are willing to break the law to avoid paying import duty.
So as much as you love your Tamiya TRF Kits you cant blame hobby co for not supporting them you have to look at everyone who is either not willing to pay for them or are buying from offshore.