Definitely not illegal. Flex tubes behind the windows attach to the windows with clips : r/lego
Technic Tube - Flexible - LEGO® Hose Flexible 22 L with Connector Ends - The shop Briques Passion
Lego Technic Robotics Mindstorms nxt Flexible Tubes Hoses Lot | #468698356
LEGO® 73590c02b 621133 - 4501980 - ToyPro
1x Lego Technic Soft Axis Hose 12L Red Flex Tube 8145 8448 4241518 32200 | eBay
LEGO Flex LEGO Bricks & Building Pieces for sale | eBay
A Brick-Built LEGO Bridge Bonanza - BrickNerd - All things LEGO and the LEGO fan community
Alerjik Parlak çekilme lego flex tube - agarethiopia.com
Flex Tube DW G2
Review: #10307 Eiffel Tower - BRICK ARCHITECT
LEGO Technic 10 pieces tube / hose light flexible. Diameter 3 mm, length 6 studs = 4.8 cm. : Amazon.nl: Toys & Games
Hose, Flexible 8.5L with Tabless Ends Black (Ends different color than Tube) : Part 73590c01b | BrickLink
LEGO® 27328pb01 6173148 - 6308533 - ToyPro
Alternative to LEGO Hose Rigid 3mm. Compatible Flex Tube for - Etsy
LEGO 6299954 FLEX TUBE, 21 MODULE, W/ 3.2 HOLE - MEDIUM NOUGAT
LEGO Light Gray Hose Flexible Tube 7L | Brick Owl - LEGO Marketplace
1x Lego Flex Hose 8,5L Black Connector Flexible Set 6285 6959 73590c01a | eBay
LEGO 6200551 FLEX TUBE, 21 MODULE, W/ 3.2 HOLE - MEDIUM LAVENDER
Lego Tuyau Gris Med Stone Grey Flex Tube 12m ref 14301 for sale online | eBay
An Adequate Substitute for 3mm Rigid Tubing (US-Only) - LEGO Train Tech - Eurobricks Forums
LEGO STAR WARS 1x New Light Grey Flex Tube Pants Rigid 3mm D. 03 length 2.4 cm 75c03 £3.13 - PicClick UK
LEGO part 57539pb03 - Trans-Clear Hose, Flexible Ribbed with 8mm Ends, 19L with Blue Center Pattern at BrickScout
Hose, Rigid 3mm D. 14L / 11.2cm : Part 75c14 | BrickLink
