I rent one-way between LAX and SNA a few times a month. I found that with both Avis and National I haven't had a premium or drop charge for one-day (same-day or next-day return) rentals starting on a Friday, Saturday, or Sunday. I looked at my records for the last three months and all had base rates of $22-$27 before taxes/fees for a mid-size. With rentals originating from LAX, there is a $10 facilities charge in addition to the other taxes/fees. If you use an Avis AWD# that offers a Pay Now rate (such as A108326 - Costco), the weekend rate is routinely around $18 before taxes/fees for LAX-LAX and LAX-SNA. I just did a quick check on Avis for pickup at LAX on 6/1/12 at 6PM with return to SNA on 6/2/12 at 6PM and get a Pay Now rate of $15.17. With taxes and fees, the total estimate is $28.92.