Cryptic crossword No 2,896

Across

1. Citroen due shortly to be repaired (9)
2. Way to ensure a response over email finally (4)
3. Caught after receiving motor racing study in secret (10)
4. Trial freeing men (4)
5. Tree knocked over by left arm (5)
6. In retrospect, mistake to sacrifice bishop in game (3)
7. Murmur softly drinking cold beverage (5)
8. Evaluating entertaining French joiner (9)
9. Do things in the wrong order to get this beast (4-5)
10. Democrat longed to be let go (7)
11. Accepted into queen’s attention (3)
12. British further defending king (7)
13. Greek character in church is snubbed (3)
14. Impurity damaged most of Luton plant (9)
15. Conclusion of superstar: 'not on' (3)
16. Check car (5)
17. Retro gentleman embodying old swagger (5)
18. Maybe Douglas remains tense (10)

Down

1. Credit so far to drop off (5)
2. Next time, prepared to bring in news outlets (9)
3. With nothing missing, a certain camper makes sauce (5)
4. Blowing top, sees red - frustrated, snorting cocaine - becomes more distant (7)
5. Food irredeemably bad apart from lime, oddly (3,5)
6. In the end, Cuba and Luxembourg running in event (9)
7. Brother’s loud song turned up (5)
8. Extremely emotionally intense film in which German dies unexpectedly (7)
9. Care about how many people saw an ad (5)
10. Equipment that keeps clutch going? (9)
11. European’s article in Bild supporting cool network (9)
12. 501s business beginning to undervalue books (8)
13. Pain following cycling exercises and run (7)
14. Brief message securing university's new architectural feature (7)
15. City’s hard light returning (5)
16. Lives above a Costa ultimately, in Hayes? (5)