ACROSS
1 Bank on 14,24, docked and flagging, being cut in a certain way (13)
8 Toll road privatised in 14,24 . . . (4)
9  . . . makes offer for the same lot (10)
10 Alpine transportation requires changing bibs, OK? (6)
11 Place where no-one inside is sick first (8)
12 No points for bumps to the head (5,4)
14,24 The extremes of really sad, mad, bad show (4,4)
15 So I will leave this and text you instead (4)
16 Change togs and greet whizz-kids (2-7)
20 The Iron Man endlessly flounders, becoming unlikeable character (4-4)
21 Portion of aspic Kate might nibble cautiously (4,2)
23 Mad about Riesling – no good going and changing chemical added to maintain balance (10)
24 See 14
25 You have to be twenty two to visit this practitioner (13)

DOWN
1 Sicko races all over the place to persevere with plan (5,2)
2 Somewhat exacerbated, leaving bitter taste in the mouth (5)
3 Above all topless, floppy and cuddly (7)
4 Waltons' image non-functioning in place of 14,24 (10-2-3)
5 History teacher in Siam joins student society (6)
6 Hide from alien wit I translated (3,2,4)
7 Di tries rehab for mugs before being washed up (7)
13 8p body suit tailored? (6,3)
15 Deadly machine toy that’s worn out (4,3)
17 Of these, one in four was a great place for novelty rock (7)
18 Free time right around commercial – welcome back! (7)
19 Arab labourer, sound chappie (6)
22 You'd be sensible not to be like this (5)