Because Aggstein Castle (Burg Aggstein) is located on top of a hill, you need to drive up a slope area before reaching the castle. Do drive carefully and slowly, and watch out for oncoming traffic especially at the bend areas where it is harder to see.
Almost nobody is visiting this area without tasting the great wines. If you are visiting the area by car it is wise to plan an overnight stay in the area because it is very hard to limit the wine tasting to the small quantity which keeps the alcohol content in the blood below 0,5 promille which are the limit for a criminal offence when driving in Austria. This is reached with the consumption of 0,25 l of wine and it needs a long time to get it out of the body.....
The police knows about the temptations, of course and so you can be quite sure that the controls are here more frequent than elsewhere in Austria and of course you would lose your driving licence at the spot and be condemned to astronomic fines and even prison when detected driving under the influence of alcohol. If you can not stay overnight in the area use public transport or buy enough bottles to enjoy the wine at home.
The ****hotel "Am Förthof" isn't worth a single cent! It doesn't keep it's promises and offers an incredible poor price-performance ratio.
I had to share my room (71 EUR!) with bugs and spider nests. Furthermore you'll have to walk to the city center for more than 1/2 an hour.