2003 Ford Mustang

I drive my boyfriends 2003 Ford Mustang convertable. I wish I knew the milage but Im no sure at the moment.

the car has been running fine until yesterday evening, My boyfriend's parents washed the car (not sure if this has something to do with it, but we hadnt had in washed in quite a while) When I picked up the car, it shuddered, kinda felt like when you dont shift up or down right in a manual (this cars an automatic)

I know nothiing about cars but I though soething to do with the transmission, but I was also informed that here is possible a hole in the manifold gasket. Could that make the car shudder and shake while accelerating/decelerating?

Any input would be greatly appreciated seeing as I ned to get back home to portland, or and at the moment im stuck about 2 1/2 ours away in washington hoping to find a bit of an answer to go off of. Myuncle is going to look at it but he works on semi-trucks not cars.

Anyways if anyone could let me know if a hole in the maifold gasket could cause the car o shake and shudder then that would be great!