hi Dude- Considering your Vehicle my view follows, >Shimla to Rampur-you will find the Best Scenic Routes (I imagined Swiss kind of View in the Drizzle Early Morning). >Rampur to Kalpa (Via Kinnaur) -you will not find any difficulties. >Kalpa to Nako and tabo - Roads are really good with couple of delays might occur due to Road widening is happening(11:30AM-2:30 PM) so try to start early from Kalpa and there are couple of stone roads for 2 km in between(your car should be ok).Khab to Tabo you will find world best Passes >Tabo to Kaza- Normal Roads. >Kaza to Losar- you should be very carefull and i prefer you to avoid National highway via Rangrik better to take Kibber and Chicham road to avoid rough patches to reach Losar,this way you will find Yaks and and other Spiti Special Species. Losar to Batkal to Chattru to Grahmpu-This is will be your most roughest patch you will come through and i will not prefer your Vehicle in this route. and you dont need to worry about your Alto Kid as this is the vehicles locals uses in Shimla>Kinnaur>nako>tabo>Kaza stretch.