Update: New instructions developed by Bumbleride provide installation options that may reduce the looseness of your infant carrier.
Attentive Z Recommends reader Aura commented that our infant car carrier was improperly strapped into the
Bumbleride Indie we reviewed last week, so I rechecked the manual to find my installation was incorrect. Instead of nesting the car seat inside the adapter bar, I attempted to latch the seat's rear clasp over the bar (which I haphazardly installed upside down). As I pored over the manual, I realized that in testing the product for review, I had happened upon the correct installation first, but the looseness of the car seat in that position triggered an instinctive urge to clip the seat over that bar just to keep it from moving from front to back.
But based on Aura's absolutely correct observation - and indeed, I had somehow convinced myself that I
did have it installed correctly - I went back to the instructions and walked through a proper install. I flipped the attachment bar into the correct position and adjusted the safety strap over the nestled seat, then took the stroller on some errands around town to see how it performed.
With these changes, the center of gravity moves closer to the ground. But the weight still tends to be in the front wedge of the triangle, causing more instability than should reasonably be acceptable for a means of transporting infants.

The attachment bar does not have a close fit with our Graco SnugRide in its correct position. There is enough space within the bars to allow the seat to slide around. The safety strap can anchor the carrier to the stroller, but it does not completely immobilize the seat. My husband Jim rocked the stroller up on its rear wheels to ascend a low curb and the carrier shifted back at least two inches in the seat.

The manual offers no guidance on the proper position of the stroller seat when using the carrier, so we tried it both ways. With the seat in an upright position, the seat is too long and rests on the attachment (as in our first photos). With the seat in a fully reclined position, the carrier has room to slide around. This sliding allows the center of gravity to from back to front and side to side simultaneously.
We tried tightening the safety strap to stop the carrier's motion, but anchors and the stroller seat would rise. Without using the carrier's notches (which are not addressed in the manual), the seat would squeeze out from under the strap if tightened beyond a certain point. In this instance, the strap would move toward the foot of the seat rather than resting at its midpoint.

The correct installation felt way too loose with a SnugRide carrier and did not inspire much confidence.
Okay, so far so good. I’m glad there were adjustments to be made but 2 more steps. I know most stroller instructions are terrible (did you ever see the baby jogger instructions? totally useless) but if you look at the illustrated picture in the instructions the seat was neither in the upright position or totally laid back. Since different car seats are different sizes I have found that adjusting the seat back to different heights somewhere in the middle can make it more secure. Also, you still have the strap on wrong. When installing the Graco Snugride in the car without the base the seat belt should be placed under the tabs on the top of the seat. If you look at the last picture with your baby you will see 2 tabs right under where the straps are resting now. Put the straps UNDER the tabs. It should stabalize it
Check out this video it shows how to install car seats in cars without bases. For some reason you have a european graco snugride because it has the place to put the shoulder belt in back (where you have the bundle me elastic) The video is not so clear but if you look at the graco booklet it will show where to put the seat belt when not using the base
http://www.thecarseatlady.com/how-to_videos/installation_video-infant_carriers_installed_without_the_base.html
@Aura, we’re all pretty sure Adrienne has a U.S. version of the Graco Snugride; it’s the 2005 model, which looks a little different than ones you see on the shelves today.
As for the install, multiple attempts to install a car seat by multiple individuals who have done this in other strollers before and have used and evaulated several very good strollers means there is a design problem at play here. Any review of this kind is also only talking about how one model of car seat fits in the stroller; the wide variety of car seats which are supposedly compatible means that some might fit better than others. One might fit perfectly. But at this point I think it’s best to conclude that the reviewer installed the car seat according to the instructions, ended up with an unsafe situation, and has shared her experiences for the benefit of the many other users likely to experience the same uncertainty and poor performance.