i read what you wrote:
I don't have a car. I'd rather you just be honest with me. Let her know the trip is only for people with Nexus cards. Does that mean you value a Nexus card over her company? Yes, it does. So own it. and i understand that what you wrote says that you believe that the OP values the nexus card over the friendship.
Valuing the card over her company
is not the same as valuing the card over her friendship
OP clearly would prefer to go through the quick line than have her friend in the car.
That doesn't make her selfish, mean or a bad friend.
But with that being the case, she needs to be honest with her friend, and she doesn't have the right to decide and announce that her friend needs to get a card.
I would just reply that I would love to go shopping with you! Have you gotten your Nexus card yet? (Yes! Great! Let's make plans).
Not responding specifically to you, YummyMummy, as to the general idea of the OP saying something to her friend that implies the friend has already got a card, or plans to get one. It's come up several times. To be honest, if I were the OP's friend, I would find this to be a combination of passive-aggressive and condescending.
From the information given by the OP, my understanding is that the friend has not communicated any intention to get a Nexus card. So for the OP to act as though her friend has said otherwise just feels "off" to me, and not very respectful.
I agree with this completely.
She can ask her friend to get one, she can arrange to meet her friend over the border, or she can decide that the time and trouble is worth it for her friend to be in the car with her.
I think OP posted (I can't find it now) that sending her on the bus would be mean. I don't follow the logic that that's worse than telling her she can't come on the trip at all because she doesn't have the card.
I would find that much worse actually, after all it's not a requirement of friendship that she always gets a lift whenever she wants one, but excluding her from the trip completely by not offering her the chance to make alternative arrangements seems silly to me.
(edited cause it got a bit quotey)