Driving with a private car through the Rhine-valley is a bit tricky, because you will hardly find any bridges there : One is in Mainz and the next one is in Koblenz and in-between you have about 100 km of a river that you may cross only at a very few places by car-ferries, and these ferries will not be operated all day long...
The large car-ferries are able to load 50 small cars or several heavy trucks, BUT they will NOT run all day and all night. In fact the ferry between St.Goar and St.Goarshausen will stop operating at 09.00p.m. and your only chance to get across the river Rhine afterwards is one of the bridges in Koblenz, about 40km downstream of St.Goar.
The river Rhine at St.Goar is quite a sensitive area, because plenty of ships have to wait there anchored for the moment, when they are allowed to go through the one-way-passage next to the Lorelei.
The ferry in St.Goar is operated
between 06.05 a.m. and 09.00p.m. on weekdays
On sundays it does not start before 08.10a.m.
It will go as soon as enough cars are onboard, or waiting at the other side of the river !
Bacharach is one of the many villages along the river Rhine, where it is really important to check for the place, where your hotel is situated. Unfortunately the railway goes through the village in quite a short distance to several hotels, while other hotels may not offer a view of the river Rhine, but you will have a great sleep, not interrupted by heavy train-trafic all day and night.
Along the river Rhine there is first a small strip of gardens, then the train-track running on the height and a row of houses, that will certainly also serve a bit as a wall against the noises of the trains.
Unfortunately some of these houses in that wall are hotels and restaurants as well - see my pictures !!