Corporate Captain noted two vehicles on their departure Runway 35L as they were nearing V1 speed and elected to continue the take off; the reporter adding that follow up communications with ATC indicated controller error.

Narrative

When departing from LRD Runway 35L; both pilots noticed two vehicles on the runway. Due to the convex [nature] of the runway surface; one end of the runway is not entirely visible from the other. By the time we noticed the vehicles; the aircraft was near V1 speed so we elected to continue. One of the vehicles was at the end of the runway and the other was about 500-1;000 FT from the end; towards the edge. Runway 35L/17R was NOTAM'd to be closed; however the ATIS did not indicate that the runway was closed. Prior to taxi; we noticed a Cessna aircraft depart 35L. We received taxi instructions to 35L and then to take off from 35L. After takeoff; due to a busy departure with weather and the Mexico border; we were unable to ask the Tower Controller about the runway. When I arrived at the destination; I called the Tower Manager to inquire about the situation. He mentioned that the Tower Controller had closed Runway 35L shortly after the Cessna aircraft had departed. The Controller then scanned Runway 35R for obstructions but incorrectly cleared us to taxi to and then take off from 35L. The Tower Manager filed a report as a Controller fault with FAA authorities. As pilots; we should have been more vigilant about the difference between the NOTAM and actual conditions. As there was a small amount of uncertainty when briefing the NOTAMs; we should have questioned the Controller's instructions.