LEGO fan and flickr.com user Ciamosław Ciamek a.k.a. PigletCiamek shared this awesome model of a U-BOOT TYP VII C in a 1/38 Scale in his photostream. This is undoubtedly the best realistic submarine model built with LEGO pieces. The size and shaping of the hull are really impressive and more amazingly the model has a fully decorated interiror. According to the description this model is 177 cm (~70 inches) long and built using approximately 15000 pieces. The builder shared detailed photos of each room with tons of detailed. You can check out the individual section details in this flickr album.
Images from the interior of the vessel. (click to enlarge)

This awesome and realisticly acurate model of the Ferrari 250 GTO in blue color was recently shared by LEGO fan and flick.com user Jens M. a.k.a. LegoExotics who is well known for his impressive car MOC's in the past. The shaping and the color blocking on this model is done greatly. According to the description the colorscheme for this model is based on an actual car which the builder saw at the Museum Enzo Ferrari. The models hood, doors and trunk can be opened and it has a detailed engine and interior as well.

This amazing scale model of the Vatican City was recently built and shared by LEGO Fan and MOC builder Rocco Buttliere who is famous for his similar impressive MOC's like "The Vernacular of the Craftsman" or "SPQR - Imperial Rome". Acoring to the photo description the scale for this creation consists more than 67000 pieces and tokk more than 800 hours to design and to build. This amount of detail on a MOC is really exceptional. I strongly recommentd to check out the photo album for detail photos.
This amazing scale model truck, "Peterbilt Quint Axle Dumptruck" was recently shared by talented LEGO builder Dennis Glaasker a.k.a. bricksonwheels who is well known for his incredible scale model MOC's. The model is very accurate to the real vehichle as the builders previous creations. According to the description this model consist of 9000 bricks and a LED system, that features over 120 LED's. Be sure to check out the builders photostream for more details of this beautiful model and other great models.

This awesome hot rod car model was recetly shared by LEGO fan and flick.com user nikolyakov in his photo stream. the builder did a gret job forming the body ısing various types of round slope pieces.My favurite part is the exhoust pipes on top of the engine. Chrome rims are also a nice touch as contrast to the dark bluish gray main body color. Check out the builders photostream for many great System and Technic MOC's.
This beautiful classic car model, Auburn 851 Boat-tail Speedster from 30's was recently shared by LEGO MOC'er Peter Blackert a.k.a. lego911 who is well known for his many great car models. The shaping of the car is really impressve and accurate to the real version. A good news for LEGO Car fans is that this MOC is actually a rebrick model for 10271 Fiat 500 set and according to the description the creator stated that he plans to provide instructions on Rebrickable for this model. I'm personally not particularly a fan of this color and would rather like to see dark colors in classic car model like dark-green or dark-red yet the builder did such a amazing job with this model that it look beautiful independent of its color.

The real car sample with the same color used for the MOC. The accurary of the shaping is probably at highest level you can achieve with available LEGO pieces, yet better ithe MOC is built only using pieces from a single set which makes it a lot of easier for LEGO fans who wants to add this classic car in their collections.
This amazingly realistic Porsche 911 RSR model was recently shared by flickr.com user
Malte Dorowski who is well known for his great car models and for his
Porsche 911 GT3 Ideas Project. The shaping of the car is really impressive. I also liked the red+gray brick-built trim lines. The doors could be opened and there is also a fully
detailed interior as well. The air-intake on the front and angles of the upper body are my other favourite sections.
I think the back of a Porsche 911 RSR couldn't be built better for this scale. the curvature achieved on top of the car is amazing as well.