I lived in Kaiserslaughten area for several years & have been back on vacations since. It was right at the end of my stay there that I became interested in the Roman history there, as well as Keltic and early Germanic.
Not specifically on the Limes but there was a huge discovery by British Captain in 1987, of the lost battlefield of the Teutoburger wald, where 3 Legions and auxilleries were totally anililated. Its near Onasbruck (not sure spelling) more north then most speculated. The place is called Kalkriese & now has a museum.
The Limes moved a lot by Heidelberg, and there were at least 3 different lines, each further east. The lines were eventually in the last stage a continual wall, except for sections along certain stretches of rivers. They essentially cut off the angle between the Rhine and the danube.
For a while the Neckar was the line, but then in one expansion it was the neckar in the south but then cut accross at Bad Wimpfen and went overland north. Then it moved westwards twice more and the neckar was completely behind the line. The last line came down from the north, along the Main for a section and crossed the Main at Miltenberg. From there it was a very straight overland wall down towards Stuggart, and then meandered towards the Danube.
I have visited some sites in that area. Aalen has nice Limes museum and remains of a Cohort castle. Miltenberg has a small museum in town, but also has a very interesting relic. A real mystery.
Its called the Tuotonstein, and is an incomplete 9 foot tall needle shaped marking or monument stone. It's shape and the spelling of Tuotons are unique. It was found buried in the ditch of an earlier Keltic Ring fort above the town, near roman alter ruins. Its done in latin with roman tools and is presumed to have been made by the romans. The inscription is in debate as to what it means, but the current most likely theory is it says "This is the border between the Teutons and the ......." (Was never finished!). It is believed to have been literally inwork on that really bad day for the romans in 260-261. Closest thing to Monty Python I know of!