Shuddering and boot only opens if vehicle is unlocked
 

Hi all, new owner of a 2006 Mazda MPV. Though i am very impressed with it's features, I am starting to think we purchased a lemon! Is it normal for the boot to unlock only if the vehicle is locked. Cant open it from inside the vehicle nor from inside button. Have to lock it with they key then only will it open from the rear handle.

It is also shuddering almost unbearably, have put new tyres and almost seems worse now. Mechanic has confirmed that the unijoint is worn ,would this be causing such bad shuddering? Cant be replaced and needs to be sent to get engineered and re- balanced. Not sure if it's worth it and if this will in fact cure the shudder.

Welcome to the forum.
Not being familiar with your car I assume it's AWD as you mention uni joints. Worn unijoints will cause a vibration. Bad shuddering again with little info is usually asociated with the clutch (assumed manual) or engine mounts.If it's an auto it may be transmission problems. More info required.