Where could I sell it?

Typical toy stores include Smyths, Toys R us, and of course sections within departments stores like IKEA, Argos. 

Posh Totty do lots of other things other than children’s toys, which may explain their slightly limited produce. I haven’t found car mats per se, but the bright colours and bold designs could mean something for my house designs themselves.

They sell toys for babies, toddlers and kids. On their website I have also found some house basket cases - baskets and containers in the shape of houses, with embroidered detail and handles. 

I have found, under ‘wooden toys’, some train track and garage construction models.

it comes with a play mat and wooden pieces, but the wooden cars would have to be bought separately.