You can try here.
http://www.race.es/servicios/ofertas_de_coches/
Not the same as the UK, but some protection.
Its not really a nightmare, but you need to be aware of the legalities and protection you have, most expats buy without understanding the language, they then don’t complain.
In general I would buy from a Spaniard as opposed a Brit, but you still need to act the same as you would in the UK.