I'm originally Spanish. The worst name ever is Angustias (Nausea). My best friend's granny was baptised Maria de las Angustias y del Pilar (Mary of the Nausea and the Pillar) but she was known as Angus...
Other names of this style...
Desamparados - Helpless
Amparo - Refuge / Shelter
Remedios - Remedies
Regla - Period. Yes, as in your monthly...
Encarnación - Incarnation
Peligros - Dangers
...
All of them are Titles of Mary. Some of them are unusual and nice, but the ones above...
I did not use any of the "nice" ones for my daughters because they sound sound odd with our surname (Scottish) but I like (and in Spain I would have used) Valme, Luz, Vega, Valle, Gádor or even Begoña.
Mercedes is pretty common, nicknames are Merce, Merche, Mer, Mery, etc. Very popular since the 1880s, after the romantically tragic Queen Mercedes, who passed away when she was just 18 years old.
The cars are named after the brand founder's daughter, Mercedes Jellinek.