Favorite new route from I-5 to Palm Springs, CA

In our quest to find the most pleasurable way to make it from I-5 South to Palm Springs we happened upon a route we had never tried before that has now now hit our "favorite" list.  Our friend Garmin always wants to take us through the grapevine and over on the 210/10 combo.  Not only is the traffic unpredictable, but the road quality is marginal as well...certainly not relaxing in any way.  Last trip we tried Hwy 58 East, connecting to the 395 south and then the 215 down to the 10.  The traffic was better than I-5 but the 395 was a bit of a two-lane nightmare with impatient truckers, RV's, and cars all trying to pass each other.  The road quality was also just as bad if not worse than the 10.  This time we took Hwy 58 East all the way to Barstow where we connected to the 247 South and then to the 62 South.  Other than the 58 it was primarily 2-lane roads with very little traffic.  Best of all it only took 20 minutes longer than the route our friend Garmin loves.  The only hair on your knuckles portion is an 8% grade right before connecting to the 62...nothing a strong foot and exhaust or compression brake can't handle and certainly beats the downhill drama of the 215.