Cant open trunk, is there access to trunk space from rear passenger seat?

The fuel pump in your 2008 Buick LaCrosse is located inside the fuel tank. Here's how you can access it:

Under the Rear Seat:

If your LaCrosse has a rear seat, you can easily access the fuel pump by removing the rear seat cushion. Look for a cover or panel under the seat. The fuel pump is usually located there.
Through the Trunk:

If your LaCrosse has an armrest in the middle of the rear seat, you'll need to go through the trunk. Remove the cover from the far back, between the back of the rear seat and the trunk space. This will give you access to the fuel pump.
Remember to disconnect the battery and follow proper safety precautions before attempting any work on the fuel pump. If you need detailed step-by-step instructions, you can refer to resources like the Buick LaCrosse repair manual or watch online tutorials.

Most passenger cars can access the trunk by taking out the rear seat.

Why are your battery cables off? Does the trunk have a key lock? With some makes and models, the rear seat back will fold down, allowing access to the trunk. If not, you may be able to remove rear seat back then see if you can access the trunk.

If the trunk release is electric, have to check wiring circuit and applicable fuse.

What is model year, I'll try to look up trunk release wiring circuit.

boot = trunk.
does not all BMW, have a lever that opens trunk from inside car?
and if you cant just tilt down the rear seat. then you cant.
takes tools. to remove it.
lost your spare factory key?
or stranded....???

find the lever. on some cars is near drivers seat other dash ,and others glove box lever.
I dont have BWM books.
but the glove box operators guide covers this, did you lose that too?

The driver's door should open with the key. Then you'll have to access the trunk through the backseat.

There is an emergency trunk release located inside the trunk. To gain access, there is a pass-through in the rear seat. Put the rear armrest down, open the pass-through, and move the release up with your fingers. The release is glow-in-the-dark. So you should have no trouble finding it using a flashlight.

To avoid getting it towed to the dealer (where they'd remove the rear seat to access the trunk),
you can get out your socket set/tool kit and remove the rear seat yourself and reach into the
trunk. If this car has fold-down rear seat(s) or bolster(s), simply fold them down and reach in.
Haynes manual (or online manuals) for this car aren't yet accessible, but a call to your Kia
dealership's service dept. may get a mechanic on the line who can give you a few good tips, or
pay a handy neighbor to figure out how to remove (and re-install) the rear seat to get access to
the trunk...

yes you can no problem their but you may have to cut the back of the seat away ,the metal behind the seat i mean to get enough space to open it with a screwdriver ,what about a a pair of pliers on the remote pull cable ??

Open the trunk manually. Pull down the back seat armrest and open the door for trunk access. There is a yellow handle that is above the door, pull the handle and the trunk will open manually.
The remedy for your problem is probably the fuse that runs the solenoid to the trunk opener, it is found under the rear seat passenger side. It has a black cover over it, remove the cover and find the corresponding fuse.

There should be a black handle beside the driver's seat, closest to the door to pull and release the trunk lock. Let me know if you need anything else.

In my '04 corolla I can unlatch the left passenger seat back by reaching behind the left seat back and sticking my finger up into the second of 3 quarter sized holes. my arm is about 15" stuck in and reaching up into the trunk about 6" back. Feel around for the holes. You can pull the latch at that point, but...you have to be flexible.