It's been a long time coming, but a complete recording of the Heidelberg Catechism in Spanish is now available:
It's also posted question by question on the same Sermonaudio page. The reading tracks with this text: https://rcus.org/wp-content/uploads/2021/12/Catecismo-de-Heidelberg-5X8.doc
El Catecismo de Heidelberg Completo
Manuel Bento | Iglesia Reformada Valle de Gracia
www.sermonaudio.com
It's also posted question by question on the same Sermonaudio page. The reading tracks with this text: https://rcus.org/wp-content/uploads/2021/12/Catecismo-de-Heidelberg-5X8.doc