My husband took about less than 30 minutes to assemble it.  Before it was put together my 18 month old was sitting inside the car part before the top was on.  He really got upset when the top of the car was put on and kept trying to get in.  He later put in his Woody doll and pushed the cart around to pick up toys.  I haven't brought it to the grocery store yet, but plan on bringing it to let him try it out (when I'm not in a rush).  The whole thing is very sturdy and easy to move, yet it won't tip over as it is pushed.  My son loves it!