Driving home with a bike held on by Seasuckers was not a relaxing experience. Constantly worried. Adding up bikes replacement value and the excess for car insurance on a claim. Not my idea of fun. But yes, they hold on like they are glued on, the sheet metal flexes when you push and pull the bike.
Mounting is a pita, but when you have no other options apart from bike in the boot with forks removed, it’s acceptable.
Car is now covered in mud that washed off the bike onto the roof of the car.
I modified mine and added a 15mm TA mount.