When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
As you are in the UK, your vehicle alarm and immobiliser system complies with Thatcham Category One. This makes it harder to steal but may also prevent locking the doors with a window ajar.
The only option I can find in the handbook is locking with the key instead of the remote:
This suggests it locks the vehicle but doesn't set the alarm although it may give an error tone for an open window .........