My dogs won’t stop whining when we go to the grooming salon, and I can’t tell why.

So, I don't know where else I can post this, so I'm hoping you can help, and I'm desperate enough as it is.. so recently we started going to a grooming salon to get our dog's hair cut, everything was fine, until the past few months, whenever we make an appointment, BOTH our dogs would start whining like really loudly and wouldn't be quiet, in fact it would be non-stop, I found it weird because whenever we go somewhere else (for example the beach), yes they would whine at first but eventually settle down. They also would stick closer to me than usual, try to go underneath the car seats, and have their tails drooped down. I tried giving them treats, and once they finished eating, they would eventually start whining again, the whole 10 min drive. Is this normal, and if so, what can I do to get them to stop? (i'm hoping this isn't considered medical..)