private car from Hong Kong airport to Jiangmen city

I like to hire a private car to take 4 people 1 way from HKIA nternational Airport to Jiangmen city in Guangdong. Can I book this service right inside the airport after my flight arrives, or is it better to make advance reservation? What's the cost for this trip?

How about taking the coaches?It's much less costly, but I am discouraged from taking these coaches because I was advised that these coaches sometime leave passengers behind if they get delayed at border crossing. How often does this happen?