How is a towbar mounted rack MORE impractical than a trailer?
You have to go 50mph everyhere, hook it on, have somewhere to store it, will make finding parking space more difficult (making shops, pubs, (accomadation) while on a biking (day)trip all the more difficult to park for), pay more on tolls (should there be any), is an AA van allowed to tow the car AND trailer? When you take the wrong turning on that back lane can you reverse half a mile to find a suitable turning round point? And as this thread is showing can be/are expensive and/or require building up from a trailer and seperate bike rack
Theres a fair few towbar mounted bike racks that tilt out of the way of the bootlid if thats one of your needs/concerns/issues: