OK, the best answer here is to get a drop off at Sheung Shui MTR station(Chinese: 上水)
There is a taxi drop off right outside the MTR and from there you travel 1 stop to Lowu or Lok Ma Chau and cross on foot. It is impossible to drop off at these border crossings because they are in securer areas open to border area residents only.

At the other side you can take train taxi or Shenzhen Metro.

For the crossing on Shenzhen bay bridge I do not know where the best chauffeur drop off point would be.