Missed opportunity - welcome to Scotland

I watched Skyfall again recently.

I'm still bothered about the fact that Bond gets out of the XJ as it has a tracker in it, but then rings Q and asks him to add a fake tracker trail for his journey to Scotland? Why would you do that? It doesn't fit, but worse, it also then raises a HUGE plot-hole noticed by many commentators. If Mallory knew they were heading to Scotland, and apparently exactly where they were heading, why did he not send any support and why leave Bond and M up there alone to die (literally for days)?

I wish instead there had been an awesome up-the-motorway car chase/battle with Bond and M in that XJ against Silva pursuers. Bond overcomes the pursuers but pretty much totals the XJ ('coz it doesn't have weapons). He then needs to change cars so he drives M and the damaged XJ to a secret lock-up near the Scottish border and picks up the DB5 there (it's weaponised so that will give them more protection). Pursuers follow the trail and find the lockup. The location means they are obviously heading for Scotland.

This would give Silva the required clue where Bond was heading; does away with Q's need for involvement; does away with the Mallory plot-hole; and would have provided another stunning action piece motorway car-chase battle for us, to keep the threat pumping toward the conclusion.

Anyway, keen for your thoughts on how that scene might have worked out better for you?