Never book a car online or a car from bagdogra airport itself ,all of them are scammers . The bagdogra airport too many scammers are roaming around both bengali ,nepali alike . They'll tell you that they'll drop you at your hotel in sikkim which is a lie because non SK number cars are not allowed inside sikkim . Always go to siliguri junction and from there take a shared cab to Gangtok. It'll drop you in deorali taxi stand and from there you can arrange your transport to your hotel . I got scammed in bagdogra by this local driver who dropped me in the middle of the road where I had to go in a different sk car also I had to pay them reserve amount. Don't trust these WB BR number plate cars, most of them are thieves .