Over time you can get carbon buildup on the valves that keep them
from closing completly. This reduces compression and can make the
car hard to start. Sedate driving leads to this since the valves
are designed to rotate at higher engine speeds (the valve rotation
helps clear the carbon buildup). With a manual transmission I bet your
car frequently is run at higher RPMs then those with automatics so
I doubt this would be a big issue. The "poor man's" tuneup (I hate
the phrase "Itailian tuneup") involves running the engine at high
RPM for about 15 minutes to blow out all this gunk.

To avoid Lawn Mowe Syndrome make sure you run the car for at least
a minute after starting it. The problem occures if you start the car,
move it (say, out of the garage) and shut it off (after about 10 seconds).
It rarely occurs but I've had it happen twice and had to wait several
hours before the car would restart (it flooded).