Can the car be immobilised while I am driving?
Never. Not while occupied, not while moving, and never for a low battery.
No. Under clause 6.3 of the rental agreement a car is never immobilised while occupied or moving, and never for a low battery. Immobilisation is limited to non-return after 48 hours notice, theft, and dangerous operation, and only an administrator can do it. You can ask for an emergency release of 24 hours, twice in a rental month, by calling +592 655-7775.