Non-boarder said to shock you in Spanish impression (3,7)

'non-boarder' is the definition.
I don't know anything about this answer so I cannot tell whether this works.

'said to shock you in spanish impression' is the wordplay.
I cannot quite see how this works, but
'said' could be 't' (I've seen this in other clues) and 't' is found in the answer.
'you' could be 'u' (commonly used in online communication) and 'u' is found in the answer.
'impression' could be 'dent' (dent is a kind of impression) and 'dent' is found within the answer.
The remaining letters 'days' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...

Can you help me to learn more?