Teaching faster fingers on cello

From Klengel to Feuillard and Pais, cellists have been writing exercises for speed and agility. Oh, and the ubiquitous Cossmann exercise: start in 4th position on the A string and play 1434 (4x) 1424 (4x) 1323 (4x), then move back a half step and repeat, moving back and repeating until you reach open A, then go across to the D, G, and C strings, continuing the finger pattern until half position on the C string is reached. 

I use these books for agility with my students: 

And my sister uses these books with her violin and viola students:

But here is an exercise I've found myself absentmindedly warming up with before recent performances. After a long drive, with cold hands; here's how I get my fingers warm.