You can try to put your bicycle inside the car lowering the rear seats and (maybe) removing the front wheel. But that way you can carry only a maximum of two bikes.
I used to carry one or two bicycles on the roof of the car (not e-bikes) and one or two bicycles in the trunk.
This cannot be an option for long term holidays if you need to carry also luggages in the trunk. Moreover carrying the bike on the roof of the car is not so safe, in my opinion. It's a lot noisy and you need to remember that the car is a lot heigher then usually.
Moreover putting bicycles on the roof of the car can be something hard for short people like me.
Putting bicycles in the trunk can be problematic after a ride in the mud...
This is of course my own opinion and it don't want to be a full examination of all the pros and cons of the various models of bicycle racks...
We have two other option to carry bicycles by car: the rear (window) ones and the tow hook ones.
You can solve most of the problems I described by using a rear bicycle rack but you cannot carry an e-bike (cause it's too heavy) and once loaded you can no longer open your trunk.
Tow hooks bike racks solve all of this problems but:
- you need (of course) a tow hook
- they costs (much) more then other ones
So I decided to buy the Volkswagen Compact III (model code 3C0071105C). This model can carry up to three bikes or e-bikes (total max load 54Kg).
It is light and compact and you can mount and unmount it very quickly.