Best and safest way to carry bikes on cars?

[Blu]

I think we need a bike carrier.
For 2 bikes. Possibly 3.

The whole idea makes me nervous because a friend's DH (very practical) fitted theirs and before the end of the road all the bikes fell off, with much damage inflicted. And last year on one long motorway drive I had to take evasive action twice because of bikes which had come off in the road . Really dangerous.

I have Skoda Roomster, which is a hatchback, with a flat van style back rather than sloping, iyswim.

What features do I need to think about?

Fiamma racks are best but pricey. I have merrily used those ones you strap on without any mishaps but would not trust on a flat back. Do you have a tow bar?

this looks good expensive but good resale value on ebay

Have no tow bar at present - I wonder how much they cost to fit?