
X4 does not have frameless doors. BMW models with frameless doors include the BMW 2 Series, BMW 4 Series, BMW Z4, BMW 3 Series GT, BMW 5 Series GT, and BMW i3. Advantages of frameless doors: They look stylish and sporty, with good sound insulation. The frameless door system automatically lowers the window by 0.5 cm when opening the door, and raises it to seal against the weatherstrip after closing. Since the weatherstrip is installed on the car body, the sealing performance is excellent. Disadvantages of frameless doors: Compared to conventional framed doors, frameless doors have higher manufacturing technical requirements, such as for sound insulation and waterproofing, resulting in higher production costs. The complex technology also increases failure rates and maintenance costs. For example, with frameless doors, only the door panel bears the load, which over time can cause loosening of window or door panel components, leading to air and water leaks. Therefore, their durability is not as good as that of framed doors.

I've driven my friend's X4, and the doors indeed don't feature a frameless design. As a crossover coupe SUV, it retains the traditional window frame structure, which results in significantly less wind noise at high speeds compared to frameless doors. One time during heavy rain on the highway, I clearly noticed the better sealing of the window frames. Frameless doors are more commonly found on the 4 Series coupe or X6, while the X4 focuses on balancing sporty styling with practicality. If you're particularly fond of frameless doors, you might want to check out the 4 Series Gran Coupe—that sloping roofline paired with frameless doors does look much more stylish.

Last week, while accompanying a friend on a test drive of the X4, I paid special attention to the doors. The metal window frames encase the entire glass, completely unlike a frameless design. The salesperson mentioned that this structure increases the body's rigidity by 15%, especially reducing deformation when going over speed bumps. Although it lacks the cool factor of frameless doors, the sound insulation and durability are more practical. To experience BMW's frameless doors, models like the X6 or the new iX incorporate this design language.

Having studied the design language of BMW's various series, the X4, as a sporty coupe SUV, opted for a traditional door structure. Its window frames are integrated with the body, unlike the 4 Series where the glass is directly embedded into the roof. While it may lack some of the flashiness, long-time owners say they don't have to worry about the glass freezing to the seals during snowy winters. In fact, the X4's fastback design paired with wide shoulders is sporty enough, and frameless doors are more suited to purebred coupes.

Just confirmed after checking the information: all current X4 models on sale come with metal window frames. Comparing the body-in-white drawings of X4 and X6, the X4's B-pillar and window frame adopt an integrated stamping process. This design provides two extra fingers of rear headroom and achieves higher side impact test scores. If frameless doors are a must, the Audi A5 Sportback is an option at the same price point, but you'll lose the SUV's ground clearance advantage.

Having thoroughly experienced the full range of products, the X4's door design proves more suitable for daily use than frameless doors. It features a hidden window frame that wraps around the upper edge of the glass, preserving the coupe's sleek lines while avoiding three common pain points of frameless doors: high-speed wind noise, aging sealing strips leading to leaks, and frozen windows in extremely cold regions. Particularly in Harbin, where temperatures can drop to minus twenty degrees Celsius, regular car owners can start their vehicles and drive off immediately, while owners of frameless doors often have to wait for the ice to melt. The X4's choice to balance style with practicality is a sensible one.


