Battlefield 3

To check how many kills you have with each vehicle go to http://battlelog.battlefield.com/bf3/gate/
Sign in and then on the top right of the page there will be a stats symbol, click this then the vehicle tab and there you go.

For this you will have to get a kill with the following vehicles. The F35B fighter jet, the BTR-90 infantry fighting vehicle and the DPV fast transport vehicle (buggy).

Pictures of the vehicles can be found here.
http://t3.gstatic.com/images?q=tbn:ANd9GcSOaPL0J5jU7g0RWkGWP...

Below are the maps that the vehicles are found on
F35B-Gulf of oman, Wake Island (US Side only)
Spawns at the US spawns on both maps, easiest if you just wait then spawn straight into the vehicle.
(If your having a hard time getting a kill with your jet an easy way to level up your jet so you can make getting the kill with it that one bit easier which has been pointed out by XPaTr0l on one of my other solutions is to play with a friend and choose the support class. Before you get in a jet, throw an ammo pack. Get in the jet, fly around when your friend is collecting your ammunition. The points you will get will count as point for the jet. You can get 100 points when your friend is reloading his gun. So you can unlock the missiles in one game.)

DPV-All maps
Most common on Wake Island and can be found at all of the flag locations.

BTR-90-Gulf of oman,Strike on Karkand, Sharqi peninsula
The easiest place to find it would be on the gulf of oman on conquest. It can be found at th RU spawn and at D when its under RU control.

These do not all have be done in one game.

Here is my Videoguide for this Achievement. You need a Kill with the DPV (Buggy) the F-35 and the BTR-90.

The Videos shows all 3 Vehicles on the Map "Gulf of Oman" because on this Map are all 3 Vehicles available.

DPV is available on both Side

F-35 is only available on US Side

BTR-90 is available on RU Side AND on the D Flag when RU has this! The BTR-90 on D is located on the Left Side of the Flag, right beside on a House.

At this D Point the US Side can get an BTR-90!

Question? Ask me in the Comments

Third Tour Achievement Guide:
Get a kill with the following vehicles: BTR-90, DPV, F-35.
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This is achievement is accumulative(you don't have to do all three kills in the same match like the "Complete Warrior" Achievement). This can only be done in Conquest(Not Conquest Assault, which is actually BULL**** and I don't like it, i which DICE would return Conquest to its normal state)
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Ok so first off you have to make sure yourself that you are ready to do this achievement as calm and tranquily possible. And always have a partner to rely on in your squad(This partner is mostly required for the DPV and BTR-90 kills).
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Instructions:
F-35:
Getting a kill with the F-35 (Main US Side B2K Fighter Jet): Ok this Jet can be found on the US Side Deployment of the following B2K Maps: Gulf of Oman and Wake Island.
If getting a kill with the F-35 is getting to annoying and difficult, try going on a Conquest on Caspian Border and try racking up some kills by killing some helicopters until you, at least unlock Flares and Heat Seekers which are necessary to make your F-35 kill easier. Or get the Engineer Kit and plant some mines over the flags and get on to the F-35 and wait till some enemy ground vehicles pass to capture the flags and eat the mines and get the F-35 Mine helped kill.
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Ok, so to get this DPV(Little anti-personal Go-kart looking like vehicle) kill, make sure you have your Squad Partner driving the vehicle while you are man-gunning the turret, try to go to an enemy non-infested area (so that you don't get killed while trying to get the kill) and kill and enemy. Or you can also drive the DPV and have your squad partner to cover you with the gunner while you try to splatter and enemy and get the kill. Or plant some mines in the flags like I said before in the F-35 kill explanation, and hope you luckily get the kill with the mines while being totally inside the DPV. :D
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Ok, this BTR-90 can only be found on the Gulf of Oman Conquest mode(Not Conquest Assault... -_-) on the RU(Russian) Side deployment or at the D flag location when at the controll and possesion of the Russian Team. So this BTR-90 kill is pretty easy but to prevent some errors while tracking up your kill for earning the achievement like having an enemy tank, jet or helicopter or even an infantry to destroy your BTR-90 before you can even earn the kill, make sure you have a partner with Engineer Kit Repair Torch Tool inside with you in the BTR-90. You can either be the Gunner or the driver, just earn a kill while inside tha tank and boom "Third Tour" achievement unlocked for 20Gs which is worth it but 20Gs are 20Gs.
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So guys if you have any problem or difficulty or if this guide isn't helpful type your question below and ask me for help. If you have any other problem to rack up any other Achievement of BF3, feel free to ask me in the comment section... BEELOOUUW. :D