Are 19" rims a good idea on my CC

[Stiggy]

Got the 17s on now and they look tiny just wondered if it would ruin the handling and or comfort too much?

[Toodeep]

A friend has done this (on 40% aspect ratio tyres and lowered) and, while you notice the difference in ride comfort, it remains acceptable. However the scuttle shake is much worse. Roof open on some roads the steering wheel and whole dashboard seem to shake and closed up you can see the door windows moving against the roof. He had it lowered because it looked odd after he'd changed the wheels and tyres.

Hard to comment on handling on London roads but when I've driven it, there are occasions when hitting potholes when the back appears to step to one side. It always seems to skip slightly to the left so I've suggested getting the people who lowered it to check their work.