American international left-back Wiley has played 26 minutes during two first-team substitute appearances since joining during the window, although he was recovering from a dislocated shoulder when he first arrived.
He showed some confident touches and a real desire to get forward, and also a decent inswinging delivery with corners and free-kicks on the right.
The Hornets grew into the game throughout the first-half, and their willingness to spread the play wide and get both full-backs forward stretched the home side at times.
Skipper Josh Mullins sent a couple of headers wide, one from a particularly good position, while it needed a great block to deny Josh Keyes.
Watford dominated the second half to such an extent that keeper Alfie Marriott could have pitched a deckchair in the sunny penalty area at Loftus Road.
To be fair to the home side they defended well against a series of attacks from the Hornets, although they required a lot of last-ditch blocks and a couple of decent saves to preserve their point.
Watford stay sixth in the Premier League Development League South table, and their next game is on Tuesday when they travel to face Bristol City.
Here’s how the game unfolded:
4 – O’Brien turned and passed to Coomes, who screwed his shot well wide.
19 – O’Brien dispossessed Gaspar and fed Coomes on the left, he shot early but just over the bar.
21 – Eames cross from the right wasn’t cleared well, the ball eventually ran back to Eames who had come inside and he shot over the target.
24 – Keyes curled in a free kick from the left flank, Mullins timed his run well and got highest, but sent his header too high.
25 – Gaspar's diagonal pass released Eames on the right, he cut in and had a shot blocked.
30 – Keyes slipped the ball wide to Massiah-Edwards who cut in and sent a shot straight at Shepperd.
31 – Corner from the right hit deep by Keyes, Mullins headed wide.
35 – Quick clearance from Sheppard got the Trialist in behind the defence down the right, Marriott had spotted it and left his box to challenge. Brought the striker down and received a yellow card.
37 – Quick break from Lawson down the left, checked and then squared for Lawson who seemed set to get a shot at goal from about 10 yards before Cuthbert dived in the way to block.
Half-time: QPR 0 Watford 0
50 – Superb interplay down the left between Massiah-Edwards and Keyes enabled Wiley to break down the flank, but his low cross evaded everyone in the six-yard box.
51 – Massiah-Edwards excellent run and pass into the box, but Adeyemo had the ball nicked off his toe by Cuthbert.
54 – An attack broke down but Massiah-Edwards won it back and then struck a superb 25-yard curling effort that hit the bar and shot up in the air. Sikiru raced in but he headed the dropping ball over the bar under pressure from Shepperd.
63 – Very neat footwork inside the box from Keyes before he flashed a shot across the face of goal.
70 – Only a superb block from Wiles denied Adeyemo from close range after he had been teed up by a right-wing cut-back from Massiah-Edwards.
85 – Ball worked in from the left and Eames struck a shot from 20 yards then Shepperd dropped to hold.
89 – Wiley clipped a free kick into the box, Keyes got a flick and Mullins’ attempt to head back into the six-yard box was gathered by Shepperd.
Full-time – QPR 0 Watford 0
Watford: Marriott; Eames, J Morris (Wiley ht), Gaspar, Mullins, Gould, Massiah-Edwards, Sikiru (Garcia-Romero 60), Adeyemo (Stephenson 79), Keyes, Lawson (Smith 82). Unused sub: S Morris