This link is still active. Cheapest for me at Doncaster M&G + Lounge and Fast Pass 2 Adults £88 for 8 days parking.
With HE and its associated sites you need to try multiple codes as some only work on some products or some suppliers My recent trawl through codes many looking for LHR many are 10% and some new ones 14% a lot of voucher sites are sending you with WM076 which is 14% The deal code(WM484) works 30% with Drivefly M&G parking but the reviews are not good. These two were 15% when I tried this week. AZ506 some providers parking and hotels.. AX568 purple parking
This link is still active. Booked meet and greet at East mids for 15 days in August for £63 and airport lounge for £99 for 5 people. Also topcashback has tracked too. Cheapest I could find.
Amazing cheap airport Meet N greet at Prima
Thanks, £8 better than skypark secure, same car park, plus small chance of quidco which has tracked.