car makes a ratteling noise while driving

It's hard to guess at the noise without being able to drive the car and experience the noise first hand. It could be sway bar links, it could be an exhaust heat shield or one of many other things. I would bring the car back to the people who replaced the struts and ask them to go for a drive with you so you could point out the exact noise you are concerned about.. It is always best to go for a ride with a service person and point out the noise so they know specifically what your concern is.