How do you say in Spanish: I didn't know if I should rent a car or go by plane
How do you say in Spanish: I didn't know if I should rent a car or go by plane.
Try "no se si mas me conviene arrendar auto (coche/carro depending where you want to do it) o viajar en avion"
This changes "should" into "suits me better" simply because that is how I would expect most of my Spanish speaking acquaintances to say it.
"mas me conviene" is inverted (instead of "me conviene mas") because it sounds better to my ear rather than because you have to do it that way round.
No supe si deberia alquilar un coche o iba en avion.
better answer already given.