I have a Hauck Lacrosse 3 in 1 but I will buy the Cybex Aton 5 (0-13kg) car seat for more road safety. Is it possible to connect them both via adapter?
Unfortunately, no, the Hauck Lacrosse pram doesn't offer a Maxi-Cosi/Cybex car seat adapters option. So, you can only use the Cybex Aton5 in your car but not on the Lacrosse stroller frame.
You can also get a very light buggy frame just to use as a travel system with your Aton - or be happy with the Lacrosse dedicated Hauck Zero Plus Comfort car seat. I mean, it's actually not the worst car seat out there, safety-wise (even if there are better) - It got an 'Acceptable' result in ADAC tests.
But, of course, the Cybex Aton 5 is better... just not compatible with this chassis.