IFR corporate aircraft inbound to CMA was denied request for RNAV approach from ZLA; reportedly because the procedure routing interfered with LAX traffic.

Narrative

On an instrument flight to Camarillo CA (CMA); close to midnight with destination tower closed; I had AWOS weather indicating marginal VFR at destination with scattered ceiling at 700. I was approaching the airport from the south on V27 to VTU. ATC was ZLA and they recommended a visual approach. I stated a preference for the RNAV-Y approach that would allow for a descent below the possible deteriorating conditions. ATC asked what approach fix I would like to start with and I gave a nearby IAF listed for the RNAV-Y approach. ATC replied that I could not do that as it interfered with approaches to LAX and said I should use another starting fix. I replied that I could use any of the additional fixes down to the FAF but the answer I got was that they would not work either as they also interfered with approaches to LAX. At this point I felt that I was getting a serious run-around by ATC as there was no other approach that I could use into CMA. I had the CMA beacon in sight from 4000 feet and 15 miles south of the field so I said I was cancelling IFR. I did cancel IFR and changed to the CMA advisory frequency while I proceeded with the visual descent. About 5 miles out it became obvious there was mixed weather at CMA. West of the field as broken at about 700; over the airport was scattered at 700; and east of the field was clear. In a visual approach to runway 26; I lost sight of the runway more than once but had a solid visual on the runway from 600 feet down. I landed without event. I feel this was marginal VFR at best and more likely IMC. I also felt this was a condition forced on me by ATC who basically seemed to not want to give me the RNAV-Y approach.